fleetd #669: pin the fleet-wide tabLabel-vs-collaborator-tab check

Adds a test driving validateLeadTabPrefixes()'s fleet-wide
fleet.tabLabel branch directly against a collaborator tab, with no
profile override involved. Every existing collaborator test exercised
only the profile-override branch below it, leaving the fleet-wide
branch without a pinning test.

fleetd/fleetd.example.yaml

@@ -669,6 +669,15 @@ fleet:
   #     kind: opencode
   #     model: openai/gpt-5.6-terra
 
+  # A collaborator tab, keyed by name (fleetd #669). This block is parsed and validated today;
+  # nothing yet recognises or addresses the tab it names. Recognise-only, like a profile-less
+  # `leaders:` entry above: there is no `profile:`, no `instances:` and no `kind:`. `tab:` is
+  # REQUIRED and is the only field identity depends on, matched case-insensitively — the same
+  # GET-THE-VALUE-RIGHT warning above the `leaders:` block applies here too.
+  # collaborators:
+  #   reviewer-alex:
+  #     tab: "collab: alex"
+
   # architects:
   #   architect-1:
   #     profile: opus                # a strong model, on the operator's subscription

fleetd/src/main/java/dev/ltms/fleet/config/FleetConfig.java

@@ -1129,11 +1129,8 @@ public record FleetConfig(
      *                            {@code tab} can never be discovered, launched or not
      * @param instances           how many of this lead should be live (default 1). The daemon
      *                            launches only the shortfall, so a restart adopts rather than doubles
-     * @param tabPrefix           no longer used to find a lead's tab — {@code tab} is matched
-     *                            exactly. Its only remaining job is the startup collision guard
-     *                            ({@link #validateLeadTabPrefixes()}), which still uses it to refuse
-     *                            a worker {@code tabLabel} template that could be misread as a lead.
-     *                            Default {@code "lead:"}
+     * @param tabPrefix           lead-tab naming convention checked against member labels. Lead
+     *                            identity uses {@code tab}. Default {@code "lead:"}
      * @param scanIntervalSeconds how long a tab scan is cached before herdr is asked again; also the
      *                            worst case before a newly-labelled tab is recognised. Default 10
      * @param kind                which agent runs there ({@code claude}, {@code opencode}, …)
@@ -1179,6 +1176,25 @@ public record FleetConfig(
         }
     }
 
+    /**
+     * A tab fleetd recognises as a collaborator, keyed by name (fleetd #669).
+     *
+     * <p>Recognise-only: there is no {@code profile}, no {@code instances} and no {@code kind}.
+     * Nothing here ever launches a pane.
+     *
+     * <p>{@code tabPrefix} is absent. Identity is matched on the exact {@code tab} alone.
+     *
+     * @param tab the exact tab label hosting this collaborator, matched case-insensitively; the
+     *            only field identity depends on. Required — an entry with no {@code tab} can
+     *            never be discovered.
+     */
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    public record Collaborator(String tab) {
+        public Collaborator {
+            tab = (tab == null || tab.isBlank()) ? null : tab.strip();
+        }
+    }
+
     /**
      * One entry of a {@code fleet:} role pool — a role paired with the backend it runs on.
      *
@@ -1216,15 +1232,18 @@ public record FleetConfig(
      * is exactly compatible with that. The pool is also what replaced {@code defaultProfile:} — an
      * unqualified spawn names a role, and the role's pool supplies the candidates.
      *
-     * @param leaders     panes that orchestrate rather than are orchestrated, keyed by lead name
-     * @param architects  profiles the {@code architect} role may run on
-     * @param developers  profiles the {@code dev} role may run on
-     * @param hunters     profiles the {@code hunter} role may run on
-     * @param reviewers   profiles the {@code reviewer} role may run on
-     * @param charters    optional launch-charter text keyed by singular role wire name
-     * @param tabLabel    template for a member tab's label; {@code {role}}, {@code {profile}},
-     *                    {@code {model}} and {@code {n}} (a per role+profile counter) are
-     *                    substituted. Default {@link #DEFAULT_TAB_LABEL}
+     * @param leaders       panes that orchestrate rather than are orchestrated, keyed by lead name
+     * @param architects    profiles the {@code architect} role may run on
+     * @param developers    profiles the {@code dev} role may run on
+     * @param hunters       profiles the {@code hunter} role may run on
+     * @param reviewers     profiles the {@code reviewer} role may run on
+     * @param charters      optional launch-charter text keyed by singular role wire name
+     * @param tabLabel      template for a member tab's label; {@code {role}}, {@code {profile}},
+     *                      {@code {model}} and {@code {n}} (a per role+profile counter) are
+     *                      substituted. Default {@link #DEFAULT_TAB_LABEL}
+     * @param collaborators tabs fleetd recognises as collaborators (fleetd #669), keyed by name.
+     *                      Recognise-only, exactly like a {@code profile}-less {@link Leader}:
+     *                      nothing here is ever auto-launched.
      */
     @JsonIgnoreProperties(ignoreUnknown = true)
     public record Fleet(Map<String, Leader> leaders,
@@ -1233,13 +1252,11 @@ public record FleetConfig(
                         Map<String, Slot> hunters,
                         Map<String, Slot> reviewers,
                         Map<String, String> charters,
-                        String tabLabel) {
+                        String tabLabel,
+                        Map<String, Collaborator> collaborators) {
 
         /**
-         * Role first, so the tab bar reads as the fleet and so the label shares a namespace with a
-         * lead's {@code tabPrefix}. Because {@code {role}} comes from a closed enum, a generated
-         * member label can never begin with {@code "lead:"} — the clash that
-         * {@link #validateLeadTabPrefixes()} used to have to check for is unrepresentable here.
+         * Role first, so the tab bar identifies the member's fleet role.
          */
         public static final String DEFAULT_TAB_LABEL = "{role}: {profile} #{n}";
 
@@ -1251,26 +1268,30 @@ public record FleetConfig(
             reviewers = unmodifiableOrEmpty(reviewers);
             charters = unmodifiableOrEmpty(charters);
             tabLabel = (tabLabel == null || tabLabel.isBlank()) ? DEFAULT_TAB_LABEL : tabLabel;
+            collaborators = unmodifiableOrEmpty(collaborators);
         }
 
         /**
-         * A fleet with no configured launch charters — the shape every deployment had before
-         * CB-566, and what most tests want.
+         * A fleet with no configured launch charters and no collaborators — the shape every
+         * deployment had before CB-566, and what most tests want.
          *
          * <p>Kept deliberately, even though an overload that drops a new field is normally the
          * shape to avoid. It is safe here because nothing <em>reads</em> a charter through a
          * constructor: the launcher reads {@code fleet.charters()} from the live config. Jackson
          * binds the canonical constructor, so this one cannot swallow an operator's YAML.
+         * {@code collaborators} is dropped the same way and for the same reason: no caller of
+         * this overload has ever needed to set it, so it defaults to empty here exactly as the
+         * canonical constructor would default an absent YAML key.
          */
         public Fleet(Map<String, Leader> leaders, Map<String, Slot> architects,
                      Map<String, Slot> developers, Map<String, Slot> reviewers,
                      Map<String, String> charters, String tabLabel) {
-            this(leaders, architects, developers, null, reviewers, charters, tabLabel);
+            this(leaders, architects, developers, null, reviewers, charters, tabLabel, null);
         }
 
         public Fleet(Map<String, Leader> leaders, Map<String, Slot> architects,
                      Map<String, Slot> developers, Map<String, Slot> reviewers, String tabLabel) {
-            this(leaders, architects, developers, null, reviewers, null, tabLabel);
+            this(leaders, architects, developers, null, reviewers, null, tabLabel, null);
         }
 
         /**
@@ -1916,7 +1937,7 @@ public record FleetConfig(
 
     /** The {@code fleet:} child blocks whose direct children are slot names. */
     private static final Set<String> FLEET_POOL_KEYS =
-            Set.of("leaders", "architects", "developers", "hunters", "reviewers");
+            Set.of("leaders", "architects", "developers", "hunters", "reviewers", "collaborators");
 
     /**
      * Reject a {@code fleet:} role pool whose slot names repeat (CB-548, re-homed by CB-557).
@@ -1926,7 +1947,7 @@ public record FleetConfig(
      * daemon would never know. Jackson's YAML parser does not fail on duplicate mapping keys by
      * default, so duplicates are caught here, at parse time, before the map is built.
      *
-     * <p>Only the five pools <em>directly under the top-level {@code fleet:}</em> are considered,
+     * <p>Only the six pools <em>directly under the top-level {@code fleet:}</em> are considered,
      * and only their direct child keys (the slot names). A nested field elsewhere, even one also
      * named {@code developers:}, is ignored, so parsing of the rest of the config is unaffected.
      *
@@ -2685,31 +2706,21 @@ public record FleetConfig(
     }
 
     /**
-     * Reject a lead-scan convention that a worker tab would also satisfy (CB-531).
+     * Reject a member tab-label template that could render as a configured lead or collaborator
+     * tab or match a lead-tab naming convention, and reject two {@code fleet.leaders} or
+     * {@code fleet.collaborators} entries — across either registry — that share one exact tab.
      *
-     * <p>The scan reads a tab label and concludes "a lead lives here". fleetd also <em>writes</em>
-     * tab labels — every member gets one rendered into its tab. Choose a lead {@code tabPrefix} that
-     * a member template matches and the daemon starts labelling its own members as leads, promoting
-     * the entire fleet to {@link dev.ltms.fleet.auth.Role#PRIMARY} with no message and no diff.
-     * {@link #validatePanePlacementAgainstLeadTabs()} is the check that stops a pane-placed member
-     * from landing inside a lead's tab in the first place; this check is a second, independent
-     * guard that catches the hazard even when every profile places members correctly, by refusing
-     * a label that a scan would still misread as a lead.
+     * <p>{@code fleet.collaborators} has no {@code tabPrefix}: identity is matched on the exact
+     * {@code tab} alone, so only the exact-render check applies there, not the prefix check.
      *
-     * <p>CB-557 shrank this check rather than removing it. The default template is
-     * {@code "{role}: {profile} #{n}"} and {@code {role}} comes from a closed enum, so a
-     * <em>generated</em> label can no longer collide by construction. What remains checkable is what
-     * an operator still writes by hand: the {@code fleet.tabLabel} template and any per-profile
-     * {@code tabLabel} override.
-     *
-     * <p>Fatal rather than a warning, unlike {@link #warnUnknownTopLevelKeys}: an unknown key means
-     * a feature does nothing, while this means a feature does the opposite of what it says.
-     *
-     * @throws IllegalStateException when the fleet template or any profile's {@code tabLabel}
-     *                               override starts with a configured lead prefix
+     * @throws IllegalStateException when the fleet template or a profile {@code tabLabel} override
+     *                               can render as a configured lead or collaborator tab or match a
+     *                               lead-tab prefix, or when two entries — of either registry, or
+     *                               one of each — carry the same exact {@code tab}
+     *                               (case-insensitively)
      */
     public void validateLeadTabPrefixes() {
-        if (fleet == null || fleet.leaders().isEmpty()) {
+        if (fleet == null) {
             return;
         }
         List<String> bad = new ArrayList<>();
@@ -2717,51 +2728,173 @@ public record FleetConfig(
             if (leader == null) {
                 return;
             }
+            String tab = leader.tab();
             String prefix = leader.tabPrefix();
-            // The fleet-wide template is checked once per prefix: it labels every member that has no
-            // override, so one bad template promotes the entire fleet, not one profile.
-            if (startsWithIgnoreCase(fleet.tabLabel(), prefix)) {
+            if (templateCanRenderAs(fleet.tabLabel(), tab)) {
+                bad.add("fleet.tabLabel=\"" + fleet.tabLabel() + "\" can render as the tab of "
+                        + "lead '" + leadName + "' (\"" + tab + "\")");
+            } else if (startsWithIgnoreCase(fleet.tabLabel(), prefix)) {
                 bad.add("fleet.tabLabel=\"" + fleet.tabLabel() + "\" starts with the tabPrefix of "
                         + "lead '" + leadName + "' (\"" + prefix + "\")");
             }
             profiles().entrySet().stream()
-                    .filter(e -> startsWithIgnoreCase(e.getValue().tabLabel(), prefix))
                     .map(Map.Entry::getKey)
                     .sorted()
-                    .forEach(p -> bad.add("profile '" + p + "' overrides tabLabel with \""
-                            + profiles().get(p).tabLabel() + "\", which starts with the tabPrefix of "
-                            + "lead '" + leadName + "' (\"" + prefix + "\")"));
+                    .forEach(p -> {
+                        String label = profiles().get(p).tabLabel();
+                        if (templateCanRenderAs(label, tab)) {
+                            bad.add("profile '" + p + "' overrides tabLabel with \"" + label
+                                    + "\", which can render as the tab of lead '" + leadName
+                                    + "' (\"" + tab + "\")");
+                        } else if (startsWithIgnoreCase(label, prefix)) {
+                            bad.add("profile '" + p + "' overrides tabLabel with \"" + label
+                                    + "\", which starts with the tabPrefix of lead '" + leadName
+                                    + "' (\"" + prefix + "\")");
+                        }
+                    });
         });
-        if (bad.isEmpty()) {
+        fleet.collaborators().forEach((collabName, collaborator) -> {
+            if (collaborator == null) {
+                return;
+            }
+            String tab = collaborator.tab();
+            if (templateCanRenderAs(fleet.tabLabel(), tab)) {
+                bad.add("fleet.tabLabel=\"" + fleet.tabLabel() + "\" can render as the tab of "
+                        + "collaborator '" + collabName + "' (\"" + tab + "\")");
+            }
+            profiles().entrySet().stream()
+                    .map(Map.Entry::getKey)
+                    .sorted()
+                    .forEach(p -> {
+                        String label = profiles().get(p).tabLabel();
+                        if (templateCanRenderAs(label, tab)) {
+                            bad.add("profile '" + p + "' overrides tabLabel with \"" + label
+                                    + "\", which can render as the tab of collaborator '"
+                                    + collabName + "' (\"" + tab + "\")");
+                        }
+                    });
+        });
+        if (!bad.isEmpty()) {
+            throw new IllegalStateException("refusing to start: " + String.join("; ", bad)
+                    + ". Every member labelled that way would be read back as a lead or "
+                    + "collaborator and granted that identity's authority. Change one of the two "
+                    + "so member tabs cannot be confused with a lead's or collaborator's tab.");
+        }
+
+        List<String> collisions = new ArrayList<>();
+        List<String> leadNames = fleet.leaders().keySet().stream().sorted().toList();
+        for (int i = 0; i < leadNames.size(); i++) {
+            String nameA = leadNames.get(i);
+            Leader a = fleet.leaders().get(nameA);
+            if (a == null || a.tab() == null || a.tab().isBlank()) {
+                continue;
+            }
+            for (int j = i + 1; j < leadNames.size(); j++) {
+                String nameB = leadNames.get(j);
+                Leader b = fleet.leaders().get(nameB);
+                if (b == null || b.tab() == null || b.tab().isBlank()) {
+                    continue;
+                }
+                if (a.tab().equalsIgnoreCase(b.tab())) {
+                    collisions.add("lead '" + nameA + "' and lead '" + nameB + "' both use tab \""
+                            + a.tab() + "\"");
+                }
+            }
+        }
+        List<String> collabNames = fleet.collaborators().keySet().stream().sorted().toList();
+        for (int i = 0; i < collabNames.size(); i++) {
+            String nameA = collabNames.get(i);
+            Collaborator a = fleet.collaborators().get(nameA);
+            if (a == null || a.tab() == null || a.tab().isBlank()) {
+                continue;
+            }
+            for (int j = i + 1; j < collabNames.size(); j++) {
+                String nameB = collabNames.get(j);
+                Collaborator b = fleet.collaborators().get(nameB);
+                if (b == null || b.tab() == null || b.tab().isBlank()) {
+                    continue;
+                }
+                if (a.tab().equalsIgnoreCase(b.tab())) {
+                    collisions.add("collaborator '" + nameA + "' and collaborator '" + nameB
+                            + "' both use tab \"" + a.tab() + "\"");
+                }
+            }
+        }
+        for (String leadName : leadNames) {
+            Leader lead = fleet.leaders().get(leadName);
+            if (lead == null || lead.tab() == null || lead.tab().isBlank()) {
+                continue;
+            }
+            for (String collabName : collabNames) {
+                Collaborator collaborator = fleet.collaborators().get(collabName);
+                if (collaborator == null || collaborator.tab() == null
+                        || collaborator.tab().isBlank()) {
+                    continue;
+                }
+                if (lead.tab().equalsIgnoreCase(collaborator.tab())) {
+                    collisions.add("lead '" + leadName + "' and collaborator '" + collabName
+                            + "' both use tab \"" + lead.tab() + "\"");
+                }
+            }
+        }
+        if (collisions.isEmpty()) {
             return;
         }
-        throw new IllegalStateException("refusing to start: " + String.join("; ", bad)
-                + ". Every member labelled that way would be read back as a lead and granted "
-                + "spawn/stop/send on the whole fleet. Change one of the two so member tabs and "
-                + "lead tabs cannot be confused.");
+        throw new IllegalStateException("refusing to start: " + String.join("; ", collisions)
+                + ". Tab identity is matched exactly, so only one of two entries sharing a tab can "
+                + "ever be found — the other is silently unreachable. Give each lead and "
+                + "collaborator its own exact tab.");
+    }
+
+    private static boolean templateCanRenderAs(String template, String tab) {
+        if (template == null || template.isBlank() || tab == null || tab.isBlank()) {
+            return false;
+        }
+        var placeholders = Pattern.compile("\\{(?:role|profile|model|n)}").matcher(template);
+        StringBuilder expression = new StringBuilder("^");
+        int literalStart = 0;
+        while (placeholders.find()) {
+            expression.append(Pattern.quote(template.substring(literalStart, placeholders.start())));
+            expression.append(".*");
+            literalStart = placeholders.end();
+        }
+        expression.append(Pattern.quote(template.substring(literalStart))).append("$");
+        return Pattern.compile(expression.toString(), Pattern.CASE_INSENSITIVE).matcher(tab).matches();
+    }
+
+    /** Case-insensitive prefix test that tolerates a null or blank label. */
+    private static boolean startsWithIgnoreCase(String label, String prefix) {
+        if (label == null || prefix == null || prefix.isBlank()) {
+            return false;
+        }
+        String stripped = label.strip();
+        return stripped.regionMatches(true, 0, prefix, 0, prefix.length());
     }
 
     /**
      * Reject a profile that places its members by {@code "pane"} while any {@code fleet.leaders}
-     * entry names a {@code tab}. A pane-placed member lands inside the focused tab rather than its
-     * own, so it can land inside a lead's own labelled tab. {@link
-     * dev.ltms.fleet.herdr.LeadTabScanner} identifies a lead purely by that tab's label — it does
-     * not exclude the member space — so a member that ends up there would be read back as the lead
-     * and granted spawn/stop/send on the whole fleet.
+     * or {@code fleet.collaborators} entry names a {@code tab}. A pane-placed member lands inside
+     * the focused tab rather than its own, so it can land inside a lead's or collaborator's own
+     * labelled tab. {@link dev.ltms.fleet.herdr.LeadTabScanner} identifies a lead or collaborator
+     * purely by that tab's label — it does not exclude the member space — so a member that ends up
+     * there would be read back as that lead or collaborator and granted that identity's authority.
      *
-     * <p>Only a leader with a non-blank {@code tab} is in scope: one with no {@code tab} feeds
+     * <p>Only an entry with a non-blank {@code tab} is in scope: one with no {@code tab} feeds
      * nothing into {@link dev.ltms.fleet.herdr.LeadTabScanner}, so it creates no hazard here.
      *
      * @throws IllegalStateException when any {@code profiles:} entry is pane-placed while any
-     *                               {@code fleet.leaders} entry names a non-blank {@code tab}
+     *                               {@code fleet.leaders} or {@code fleet.collaborators} entry
+     *                               names a non-blank {@code tab}
      */
     public void validatePanePlacementAgainstLeadTabs() {
-        if (fleet == null || fleet.leaders().isEmpty()) {
+        if (fleet == null) {
             return;
         }
         boolean anyLeaderHasTab = fleet.leaders().values().stream()
                 .anyMatch(leader -> leader != null && leader.tab() != null && !leader.tab().isBlank());
-        if (!anyLeaderHasTab) {
+        boolean anyCollaboratorHasTab = fleet.collaborators().values().stream()
+                .anyMatch(c -> c != null && c.tab() != null && !c.tab().isBlank());
+        if (!anyLeaderHasTab && !anyCollaboratorHasTab) {
             return;
         }
         List<String> bad = new ArrayList<>();
@@ -2774,10 +2907,11 @@ public record FleetConfig(
             return;
         }
         throw new IllegalStateException("refusing to start: profile(s) " + bad
-                + " use placement: pane while fleet.leaders names a tab. A pane-placed member can "
-                + "land inside a lead's labelled tab and be read back as the lead, granted "
-                + "spawn/stop/send on the whole fleet. Set placement: tab for each named profile, "
-                + "or remove the tab from every fleet.leaders entry.");
+                + " use placement: pane while fleet.leaders or fleet.collaborators names a tab. A "
+                + "pane-placed member can land inside that labelled tab and be read back as the "
+                + "lead or collaborator, granted that identity's authority. Set placement: tab for "
+                + "each named profile, or remove the tab from every fleet.leaders and "
+                + "fleet.collaborators entry.");
     }
 
     /**
@@ -2800,15 +2934,6 @@ public record FleetConfig(
         }
     }
 
-    /** Case-insensitive prefix test that tolerates a null/blank label. */
-    private static boolean startsWithIgnoreCase(String label, String prefix) {
-        if (label == null || prefix == null || prefix.isBlank()) {
-            return false;
-        }
-        String stripped = label.strip();
-        return stripped.regionMatches(true, 0, prefix, 0, prefix.length());
-    }
-
     /**
      * Reject a subscription profile whose {@code env:} block tries to reseat the Anthropic binding
      * (CB-542).
@@ -2893,8 +3018,14 @@ public record FleetConfig(
      * so duplicates are unrepresentable by construction once loaded — and {@link #load(Path)}
      * already rejects a duplicated slot name at parse time, before the map collapses.
      *
-     * @throws IllegalStateException when a slot names no profile or an unknown one, or when a lead
-     *                               can be neither found nor created, naming the offending entry
+     * <p>Also rejects a {@code fleet.collaborators} entry with no (or a blank) {@code tab}. A
+     * {@code profile}-less lead is still useful recognise-only — {@code tab} is the only field
+     * that matters to it either way. A collaborator carries no other field at all, so a blank
+     * {@code tab} leaves nothing for the entry to mean.
+     *
+     * @throws IllegalStateException when a slot names no profile or an unknown one, when a lead
+     *                               can be neither found nor created, or when a collaborator names
+     *                               no tab, naming the offending entry
      */
     public void validateMembers() {
         if (fleet == null) {
@@ -2932,6 +3063,16 @@ public record FleetConfig(
                         + "auto-launched, labelled) purely by its tab, so every entry must name one.");
             }
         });
+        fleet.collaborators().forEach((name, collaborator) -> {
+            if (collaborator == null) {
+                return;
+            }
+            if (collaborator.tab() == null || collaborator.tab().isBlank()) {
+                bad.add("fleet.collaborators." + name + " has no tab: — a collaborator is "
+                        + "recognised purely by its tab, and carries no other field, so every "
+                        + "entry must name one.");
+            }
+        });
         if (!bad.isEmpty()) {
             throw new IllegalStateException("refusing to start: " + String.join(" ", bad));
         }

fleetd/src/test/java/dev/ltms/fleet/config/FleetConfigTest.java

@@ -676,12 +676,8 @@ class FleetConfigTest {
         assertEquals(5, hb.quietNudgeCap());
     }
 
-    /**
-     * The hazard the guard exists for: fleetd writes worker tab labels and reads lead tab labels.
-     * Overlap the two and every worker it spawns is read back as a lead.
-     */
     @Test
-    void aLeadPrefixThatAProfileTabLabelOverrideAlsoMatchesRefusesToStart(@TempDir Path dir)
+    void aProfileTabLabelOverrideMatchingALeadTabRefusesToStart(@TempDir Path dir)
             throws Exception {
         Path f = dir.resolve("collide.yaml");
         Files.writeString(f, """
@@ -689,32 +685,33 @@ class FleetConfigTest {
                   port: 8080
                 profiles:
                   gx10:
-                    tabLabel: "lead: {profile} #{n}"
+                    tabLabel: "alpha"
                 fleet:
                   leaders:
                     opus:
-                      tab: "lead: opus"
-                      tabPrefix: "lead:"
+                      tab: "alpha"
                 """);
         FleetConfig cfg = FleetConfig.load(f);
 
         IllegalStateException e =
                 assertThrows(IllegalStateException.class, cfg::validateLeadTabPrefixes);
         assertTrue(e.getMessage().contains("gx10"), "the message must name the offending profile");
+        assertTrue(e.getMessage().contains("alpha"), "the message must name the offending label");
     }
 
-    /** A bad fleet-wide template promotes every member, not one profile — so it is checked too. */
     @Test
-    void aFleetTabLabelThatMatchesALeadPrefixRefusesToStart(@TempDir Path dir) throws Exception {
+    void aFleetTabLabelTemplateThatCanRenderAsALeadTabRefusesToStart(@TempDir Path dir) throws Exception {
         Path f = dir.resolve("collide-template.yaml");
         Files.writeString(f, """
                 bind:
                   port: 8080
+                profiles:
+                  pha: {}
                 fleet:
-                  tabLabel: "lead: {role} {profile}"
+                  tabLabel: "al{profile}"
                   leaders:
                     opus:
-                      tab: "lead: opus"
+                      tab: "alpha"
                 """);
         FleetConfig cfg = FleetConfig.load(f);
 
@@ -723,12 +720,28 @@ class FleetConfigTest {
         assertTrue(e.getMessage().contains("fleet.tabLabel"));
     }
 
-    /**
-     * The point of making role the label's first field: {@code {role}} comes from a closed enum, so
-     * a generated label cannot begin with {@code "lead:"} however the fleet is configured.
-     */
     @Test
-    void theDefaultTabLabelCannotCollideWithTheDefaultLeadPrefix(@TempDir Path dir) throws Exception {
+    void anExactFleetTabLabelCollisionRefusesToStart(@TempDir Path dir) throws Exception {
+        Path f = dir.resolve("exact-tab-collision.yaml");
+        Files.writeString(f, """
+                bind:
+                  port: 8080
+                fleet:
+                  tabLabel: "alpha"
+                  leaders:
+                    alpha:
+                      tab: "alpha"
+                """);
+
+        IllegalStateException e = assertThrows(IllegalStateException.class,
+                () -> FleetConfig.load(f).validateAll());
+        assertTrue(e.getMessage().contains("fleet.tabLabel"),
+                "the message must name the offending label");
+        assertTrue(e.getMessage().contains("alpha"), "the message must name the colliding lead tab");
+    }
+
+    @Test
+    void aFleetTabLabelTemplateThatCannotRenderAsALeadTabIsAllowed(@TempDir Path dir) throws Exception {
         Path f = dir.resolve("ok.yaml");
         Files.writeString(f, """
                 bind:
@@ -737,17 +750,13 @@ class FleetConfigTest {
                   gx10:
                     baseUrl: http://gx00.gw:8000
                 fleet:
+                  tabLabel: "worker-{profile}"
                   leaders:
                     opus:
-                      tab: "lead: opus"
+                      tab: "alpha"
                 """);
 
-        assertDoesNotThrow(() -> FleetConfig.load(f).validateLeadTabPrefixes());
-        for (MemberRole role : MemberRole.values()) {
-            assertFalse(FleetConfig.Fleet.DEFAULT_TAB_LABEL
-                            .replace("{role}", role.wireName()).startsWith("lead:"),
-                    "no role renders a label that reads as a lead");
-        }
+        assertDoesNotThrow(() -> FleetConfig.load(f).validateAll());
     }
 
     @Test
@@ -765,6 +774,78 @@ class FleetConfigTest {
                 "a label that collides with a convention nobody reads is not a problem");
     }
 
+    /**
+     * fleetd #677: identity is matched on a lead's exact {@code tab} alone, so two leads sharing
+     * one tab means only one of them is ever found — the guard must catch this independently of
+     * the member-template checks above.
+     */
+    @Test
+    void twoLeadsSharingTheSameExactTabRefusesToStart(@TempDir Path dir) throws Exception {
+        Path f = dir.resolve("shared-tab.yaml");
+        Files.writeString(f, """
+                bind:
+                  port: 8080
+                fleet:
+                  leaders:
+                    opus:
+                      tab: "shared tab"
+                    sonnet:
+                      tab: "shared tab"
+                """);
+        FleetConfig cfg = FleetConfig.load(f);
+
+        IllegalStateException e =
+                assertThrows(IllegalStateException.class, cfg::validateLeadTabPrefixes);
+        assertTrue(e.getMessage().contains("opus"), "the message must name one offending lead");
+        assertTrue(e.getMessage().contains("sonnet"), "the message must name the other offending lead");
+    }
+
+    /**
+     * fleetd #693: the guard matches tabs case-insensitively, because
+     * {@code LeadTabScanner} keys its tab map on a lowercased label — two tabs differing only in
+     * case collide there too, and the guard must catch that independently of the exact-match case
+     * above.
+     */
+    @Test
+    void twoLeadsSharingTheSameTabInDifferentCaseRefusesToStart(@TempDir Path dir) throws Exception {
+        Path f = dir.resolve("shared-tab-case.yaml");
+        Files.writeString(f, """
+                bind:
+                  port: 8080
+                fleet:
+                  leaders:
+                    opus:
+                      tab: "Shared Tab"
+                    sonnet:
+                      tab: "shared tab"
+                """);
+        FleetConfig cfg = FleetConfig.load(f);
+
+        IllegalStateException e =
+                assertThrows(IllegalStateException.class, cfg::validateLeadTabPrefixes);
+        assertTrue(e.getMessage().contains("opus"), "the message must name one offending lead");
+        assertTrue(e.getMessage().contains("sonnet"), "the message must name the other offending lead");
+    }
+
+    /** Control for {@link #twoLeadsSharingTheSameExactTabRefusesToStart}: distinct tabs load cleanly. */
+    @Test
+    void twoLeadsWithDistinctExactTabsAreAllowed(@TempDir Path dir) throws Exception {
+        Path f = dir.resolve("distinct-tabs.yaml");
+        Files.writeString(f, """
+                bind:
+                  port: 8080
+                fleet:
+                  leaders:
+                    opus:
+                      tab: "opus tab"
+                    sonnet:
+                      tab: "sonnet tab"
+                """);
+        FleetConfig cfg = FleetConfig.load(f);
+
+        assertDoesNotThrow(cfg::validateLeadTabPrefixes);
+    }
+
     // ── validatePanePlacementAgainstLeadTabs ────────────────────────────────────────────────────
 
     /**
@@ -919,6 +1000,273 @@ class FleetConfigTest {
                 "no primary.terminal pin ⇒ nothing registered, even with fleet.leaders configured");
     }
 
+    // ── fleetd #669: the collaborators registry ────────────────────────────────────────────────
+
+    /**
+     * {@code Fleet} is {@code @JsonIgnoreProperties(ignoreUnknown = true)}, so a config naming
+     * {@code fleet.collaborators.<name>.tab} loads with no exception whether or not the key is
+     * ever read into the object model. Asserting only "no exception" would pass both before and
+     * after the real fix, so this asserts the parsed value is actually reachable from the loaded
+     * {@code FleetConfig} — the one thing a vacuous "no exception" test cannot tell apart.
+     */
+    @Test
+    void collaboratorsBlockIsActuallyParsedNotSilentlyDropped(@TempDir Path dir) throws Exception {
+        Path f = dir.resolve("collaborators.yaml");
+        Files.writeString(f, """
+                bind:
+                  port: 8080
+                fleet:
+                  collaborators:
+                    reviewer-alex:
+                      tab: "collab: alex"
+                """);
+
+        FleetConfig cfg = FleetConfig.load(f);
+        assertEquals("collab: alex", cfg.fleet().collaborators().get("reviewer-alex").tab());
+    }
+
+    /** A collaborator carries no field other than {@code tab}, so a blank one is meaningless. */
+    @Test
+    void aCollaboratorWithNoTabRefusesToStart(@TempDir Path dir) throws Exception {
+        Path f = dir.resolve("useless-collaborator.yaml");
+        Files.writeString(f, """
+                bind:
+                  port: 8080
+                fleet:
+                  collaborators:
+                    ghost: {}
+                """);
+        FleetConfig cfg = FleetConfig.load(f);
+
+        IllegalStateException e = assertThrows(IllegalStateException.class, cfg::validateMembers);
+        assertTrue(e.getMessage().contains("ghost"), "the message must name the useless entry");
+        assertTrue(e.getMessage().contains("tab:"), "the message must say what is missing");
+    }
+
+    /** Control for {@link #aCollaboratorWithNoTabRefusesToStart}: a named tab loads cleanly. */
+    @Test
+    void aCollaboratorWithATabIsAllowed(@TempDir Path dir) throws Exception {
+        Path f = dir.resolve("named-collaborator.yaml");
+        Files.writeString(f, """
+                bind:
+                  port: 8080
+                fleet:
+                  collaborators:
+                    reviewer-alex:
+                      tab: "collab: alex"
+                """);
+        FleetConfig cfg = FleetConfig.load(f);
+
+        assertDoesNotThrow(cfg::validateMembers);
+    }
+
+    /**
+     * fleetd #669: the fleet-wide {@code tabLabel} template can render as a collaborator tab, the
+     * same hazard {@link #aFleetTabLabelTemplateThatCanRenderAsALeadTabRefusesToStart} covers on
+     * the lead side. Drives the fleet-wide branch directly, with no profile override involved.
+     */
+    @Test
+    void aFleetTabLabelTemplateThatCanRenderAsACollaboratorTabRefusesToStart(@TempDir Path dir)
+            throws Exception {
+        Path f = dir.resolve("collide-template-collaborator.yaml");
+        Files.writeString(f, """
+                bind:
+                  port: 8080
+                fleet:
+                  tabLabel: "al{profile}"
+                  collaborators:
+                    alex:
+                      tab: "alpha"
+                """);
+        FleetConfig cfg = FleetConfig.load(f);
+
+        IllegalStateException e =
+                assertThrows(IllegalStateException.class, cfg::validateLeadTabPrefixes);
+        assertTrue(e.getMessage().contains("fleet.tabLabel"));
+        assertTrue(e.getMessage().contains("alex"), "the message must name the offending collaborator");
+    }
+
+    /**
+     * fleetd #669: a member tabLabel that can render as a configured collaborator tab is the same
+     * hazard as the lead case above — a member labelled that way is read back as the collaborator.
+     */
+    @Test
+    void aProfileTabLabelOverrideMatchingACollaboratorTabRefusesToStart(@TempDir Path dir)
+            throws Exception {
+        Path f = dir.resolve("collide-collaborator.yaml");
+        Files.writeString(f, """
+                bind:
+                  port: 8080
+                profiles:
+                  gx10:
+                    tabLabel: "collab-tab"
+                fleet:
+                  collaborators:
+                    alex:
+                      tab: "collab-tab"
+                """);
+        FleetConfig cfg = FleetConfig.load(f);
+
+        IllegalStateException e =
+                assertThrows(IllegalStateException.class, cfg::validateLeadTabPrefixes);
+        assertTrue(e.getMessage().contains("gx10"), "the message must name the offending profile");
+        assertTrue(e.getMessage().contains("collab-tab"), "the message must name the offending label");
+    }
+
+    /** Control: a profile tabLabel that cannot render as the collaborator tab is allowed. */
+    @Test
+    void aProfileTabLabelThatCannotRenderAsACollaboratorTabIsAllowed(@TempDir Path dir)
+            throws Exception {
+        Path f = dir.resolve("ok-collaborator.yaml");
+        Files.writeString(f, """
+                bind:
+                  port: 8080
+                profiles:
+                  gx10:
+                    tabLabel: "worker-{profile}"
+                fleet:
+                  collaborators:
+                    alex:
+                      tab: "collab-tab"
+                """);
+        FleetConfig cfg = FleetConfig.load(f);
+
+        assertDoesNotThrow(cfg::validateLeadTabPrefixes);
+    }
+
+    /** fleetd #669: identity is matched on a collaborator's exact tab, so two sharing one are unreachable. */
+    @Test
+    void twoCollaboratorsSharingTheSameExactTabRefusesToStart(@TempDir Path dir) throws Exception {
+        Path f = dir.resolve("shared-collaborator-tab.yaml");
+        Files.writeString(f, """
+                bind:
+                  port: 8080
+                fleet:
+                  collaborators:
+                    alex:
+                      tab: "shared tab"
+                    sam:
+                      tab: "Shared Tab"
+                """);
+        FleetConfig cfg = FleetConfig.load(f);
+
+        IllegalStateException e =
+                assertThrows(IllegalStateException.class, cfg::validateLeadTabPrefixes);
+        assertTrue(e.getMessage().contains("alex"), "the message must name one offending collaborator");
+        assertTrue(e.getMessage().contains("sam"), "the message must name the other offending collaborator");
+    }
+
+    /** Control for {@link #twoCollaboratorsSharingTheSameExactTabRefusesToStart}: distinct tabs load cleanly. */
+    @Test
+    void twoCollaboratorsWithDistinctExactTabsAreAllowed(@TempDir Path dir) throws Exception {
+        Path f = dir.resolve("distinct-collaborator-tabs.yaml");
+        Files.writeString(f, """
+                bind:
+                  port: 8080
+                fleet:
+                  collaborators:
+                    alex:
+                      tab: "alex tab"
+                    sam:
+                      tab: "sam tab"
+                """);
+        FleetConfig cfg = FleetConfig.load(f);
+
+        assertDoesNotThrow(cfg::validateLeadTabPrefixes);
+    }
+
+    /**
+     * fleetd #669: a collaborator tab equal to a lead tab crosses a privilege boundary — the worst
+     * of the three new collisions, since only one of the two identities is ever found.
+     */
+    @Test
+    void aCollaboratorTabEqualToALeadTabRefusesToStart(@TempDir Path dir) throws Exception {
+        Path f = dir.resolve("lead-collaborator-collision.yaml");
+        Files.writeString(f, """
+                bind:
+                  port: 8080
+                fleet:
+                  leaders:
+                    opus:
+                      tab: "shared tab"
+                  collaborators:
+                    alex:
+                      tab: "Shared Tab"
+                """);
+        FleetConfig cfg = FleetConfig.load(f);
+
+        IllegalStateException e =
+                assertThrows(IllegalStateException.class, cfg::validateLeadTabPrefixes);
+        assertTrue(e.getMessage().contains("opus"), "the message must name the offending lead");
+        assertTrue(e.getMessage().contains("alex"), "the message must name the offending collaborator");
+    }
+
+    /** Control for {@link #aCollaboratorTabEqualToALeadTabRefusesToStart}: distinct tabs load cleanly. */
+    @Test
+    void aLeadAndACollaboratorWithDistinctTabsAreAllowed(@TempDir Path dir) throws Exception {
+        Path f = dir.resolve("lead-collaborator-ok.yaml");
+        Files.writeString(f, """
+                bind:
+                  port: 8080
+                fleet:
+                  leaders:
+                    opus:
+                      tab: "lead tab"
+                  collaborators:
+                    alex:
+                      tab: "collab tab"
+                """);
+        FleetConfig cfg = FleetConfig.load(f);
+
+        assertDoesNotThrow(cfg::validateLeadTabPrefixes);
+    }
+
+    /**
+     * fleetd #669: a pane-placed member can land in a collaborator's labelled tab exactly as it
+     * can land in a lead's — {@code validatePanePlacementAgainstLeadTabs()} must fire even when
+     * {@code fleet.leaders} is empty, which is the early-return the brief flagged as the bug.
+     */
+    @Test
+    void aPanePlacedProfileWithACollaboratorTabRefusesToStartEvenWithNoLeaders(@TempDir Path dir)
+            throws Exception {
+        Path f = dir.resolve("pane-hazard-collaborator.yaml");
+        Files.writeString(f, """
+                bind:
+                  port: 8080
+                profiles:
+                  gx10:
+                    placement: pane
+                fleet:
+                  collaborators:
+                    alex:
+                      tab: "collab: alex"
+                """);
+        FleetConfig cfg = FleetConfig.load(f);
+
+        IllegalStateException e = assertThrows(IllegalStateException.class,
+                cfg::validatePanePlacementAgainstLeadTabs);
+        assertTrue(e.getMessage().contains("gx10"), "the message must name the offending profile");
+    }
+
+    /** Control: a pane-placed profile with no lead or collaborator tab configured is allowed. */
+    @Test
+    void aPanePlacedProfileWithNoLeaderOrCollaboratorTabIsAllowed(@TempDir Path dir) throws Exception {
+        Path f = dir.resolve("pane-no-tab-at-all.yaml");
+        Files.writeString(f, """
+                bind:
+                  port: 8080
+                profiles:
+                  gx10:
+                    placement: pane
+                fleet:
+                  collaborators:
+                    alex: {}
+                """);
+
+        assertDoesNotThrow(() -> FleetConfig.load(f).validatePanePlacementAgainstLeadTabs(),
+                "a collaborator with no tab feeds nothing into the scanner, so pane placement is safe");
+    }
+
     // ── CB-548: the architects registry ────────────────────────────────────────────────────────
 
     @Test
@@ -1191,6 +1539,60 @@ class FleetConfigTest {
         assertEquals(Set.of("sonnet"), cfg.fleet().pool(MemberRole.REVIEWER).keySet());
     }
 
+    /**
+     * A duplicated name in {@code fleet.collaborators} is refused at parse time, like any other
+     * {@code fleet:} pool. See {@link #duplicateSlotNamesInOnePoolAreRejectedAtParseTime}.
+     */
+    @Test
+    void duplicateCollaboratorNamesAreRejectedAtParseTime(@TempDir Path dir) throws Exception {
+        Path f = dir.resolve("collaborator-dup.yaml");
+        Files.writeString(f, """
+                bind:
+                  port: 8080
+                fleet:
+                  collaborators:
+                    alex:
+                      tab: "collab: alex"
+                    alex:
+                      tab: "collab: alex, second"
+                """);
+
+        IllegalStateException e =
+                assertThrows(IllegalStateException.class, () -> FleetConfig.load(f));
+        assertTrue(e.getMessage().contains("alex"),
+                "the refusal names the duplicated entry, was: " + e.getMessage());
+        assertTrue(e.getMessage().contains("fleet.collaborators"),
+                "the refusal names the pool the duplicate is in, was: " + e.getMessage());
+    }
+
+    /**
+     * Control for {@link #duplicateCollaboratorNamesAreRejectedAtParseTime}: the same name reused
+     * across the collaborators registry and a member role pool is the role × profile matrix doing
+     * its job in the other pool, not a mistake — only a repeat within one pool loses an entry.
+     */
+    @Test
+    void theSameNameInCollaboratorsAndAnotherPoolIsNotADuplicate(@TempDir Path dir) throws Exception {
+        Path f = dir.resolve("collaborator-cross-pool.yaml");
+        Files.writeString(f, """
+                bind:
+                  port: 8080
+                profiles:
+                  sonnet:
+                    baseUrl: http://gx10.gw:8000
+                fleet:
+                  architects:
+                    alex:
+                      profile: sonnet
+                  collaborators:
+                    alex:
+                      tab: "collab: alex"
+                """);
+
+        FleetConfig cfg = assertDoesNotThrow(() -> FleetConfig.load(f));
+        assertEquals(Set.of("alex"), cfg.fleet().pool(MemberRole.ARCHITECT).keySet());
+        assertEquals(Set.of("alex"), cfg.fleet().collaborators().keySet());
+    }
+
     @Test
     void duplicateKeysOutsideTheFleetPoolsAreUnaffected(@TempDir Path dir) throws Exception {
         // The duplicate check is scoped to the fleet pools — a duplicate elsewhere is not this

fleetd/src/test/java/dev/ltms/fleet/config/FleetConfigValidateAllTest.java

@@ -17,63 +17,21 @@ import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 /**
- * The gap this class exists to close: mutation testing on the fleetd ticket "central allow-list
- * of usable models" found that although {@link FleetConfig#validateModels()}'s own logic was well
- * pinned, nothing proved either real caller ({@code Fleetd.main} and {@link ConfigRef#reload()})
- * still invoked it — deleting the call site left the full suite green (1478/0/0/0). A follow-up
- * measurement (same technique — remove one call site, run the suite, not read the code) found the
- * SAME gap for all five of {@link FleetConfig}'s other validators at startup, and for four of the
- * six inside {@link ConfigRef#reload()}. This is a class of gap, not one line's mistake: every one
- * of those thirteen tests called the validator itself directly, never the real caller that was
- * supposed to.
+ * Tests the reflective validator sweep and {@link FleetConfig#validateAll()} reachability.
  *
- * <p>The fix replaces the six individual {@code cfg.validateXxx()} calls at each of the two real
- * call sites with one {@link FleetConfig#validateAll()}, which reaches every validator by
- * reflection rather than by a hand-maintained list of names. A hand-maintained list of six names
- * would have exactly the defect it replaces: the seventh validator someone adds next month has no
- * reason to be added to it, and nothing would say so. This class proves TWO separate claims, and
- * keeps them separate on purpose:
- *
- * <ol>
- *   <li>{@link #theSweepMechanismIsGenericNotHardcodedToFleetConfigsSixNames()} and its neighbours
- *       prove the reflective sweep itself ({@link FleetConfig#invokeAllValidators}) is a general
- *       mechanism — it runs whatever public, no-arg, void {@code validateXxx()} methods a class
- *       happens to declare today, including a class with more of them than {@link FleetConfig}
- *       has right now. This is the proof that a future, real seventh validator on {@link
- *       FleetConfig} would be swept automatically, without needing to add a real (unwanted)
- *       seventh validator just to exercise the claim.</li>
- *   <li>{@link #validateAllReachesEveryOneOfTodaysRealValidators()} proves {@link
- *       FleetConfig#validateAll()} itself is wired to that same generic mechanism and genuinely
- *       reaches every one of today's real validators — reusing the exact minimal failing
- *       configurations {@code FleetConfigTest} already established for each one directly, plus a
- *       dedicated fixture for {@link FleetConfig#validateLeadRollover()}, which no other test
- *       drives through {@code validateAll()} — so a single call to {@code validateAll()} is shown
- *       to reproduce every one of those failures.</li>
- * </ol>
- *
- * <p>Together with the direct-{@code Fleetd.main}-invocation tests in {@code
- * FleetdStartupValidationTest} (which prove the real startup call site still calls {@code
- * validateAll()}) and the {@code ConfigRefTest} reload tests (which prove the same for {@link
- * ConfigRef#reload()}), removing {@code cfg.validateAll();} from either real call site now fails
- * a test in this module.
- *
- * <p><b>What is NOT pinned, measured rather than assumed.</b> Reverting {@link
- * FleetConfig#validateAll()} to a hardcoded list of today's method calls leaves the whole
- * suite green. Nothing ties {@code validateAll()} to
- * the generic sweep — claim 1 proves {@link FleetConfig#invokeAllValidators} is generic, and claim
- * 2 proves {@code validateAll()} reaches today's validators, and a hardcoded list satisfies both. So the
- * reflective sweep is a convenience, not the guarantee. The guarantee is {@link
- * #fleetConfigDeclaresExactlyTheseValidatorsToday()}: it fails the moment any validator is added
- * or removed, which forces whoever changes the set to look at this file.
+ * <p>{@link #theSweepRunsEveryValidateMethodOnAnUnrelatedClass()} and its neighbours
+ * prove that {@link FleetConfig#invokeAllValidators} runs each public, no-arg, void
+ * {@code validateXxx()} method on its target. {@link #fleetConfigDeclaresExactlyTheseValidatorsToday()}
+ * is the canary for the validator set. {@link #validateAllReachesEveryOneOfTodaysRealValidators()}
+ * is the reachability check for that set.
  */
 class FleetConfigValidateAllTest {
 
-    // ── Claim 1: the reflective sweep is a general mechanism, not six names in disguise ──────────
+    // ── Claim 1: the reflective sweep is a general mechanism ─────────────────────────────────────
 
     /**
-     * A throwaway fixture class, unrelated to {@link FleetConfig} in every way except shape: three
-     * public, no-arg, void methods named {@code validateXxx}. Proves the sweep works on ANY class
-     * with this shape, not on something special-cased to {@link FleetConfig}.
+     * Fixture with public, no-arg, void methods named {@code validateXxx}. It proves the sweep uses
+     * the target's method shape rather than special handling for {@link FleetConfig}.
      */
     static class ThreeValidators {
         final List<String> ran = new ArrayList<>();
@@ -92,7 +50,7 @@ class FleetConfigValidateAllTest {
     }
 
     @Test
-    void theSweepMechanismIsGenericNotHardcodedToFleetConfigsSixNames() {
+    void theSweepRunsEveryValidateMethodOnAnUnrelatedClass() {
         ThreeValidators target = new ThreeValidators();
         FleetConfig.invokeAllValidators(target);
         assertEquals(List.of("validateAlpha", "validateBeta", "validateGamma"), target.ran,
@@ -102,12 +60,8 @@ class FleetConfigValidateAllTest {
     }
 
     /**
-     * The core of the "self-maintaining" requirement: the exact same class shape as {@link
-     * ThreeValidators}, plus one more method — standing in for "a developer adds a validator next
-     * month". Nothing about the sweep changes to pick it up; the new method is invoked purely
-     * because it exists and matches the shape. This is what makes adding a seventh real validator
-     * to {@link FleetConfig} safe without touching {@link FleetConfig#validateAll()} or either
-     * call site — there is no "wire it in" step left to forget.
+     * Fixture with an added valid method. It proves the sweep reaches a method because it matches
+     * the validator shape.
      */
     static class FourValidators {
         final List<String> ran = new ArrayList<>();
@@ -135,7 +89,7 @@ class FleetConfigValidateAllTest {
         FleetConfig.invokeAllValidators(target);
         assertEquals(List.of("validateAlpha", "validateBeta", "validateDelta", "validateGamma"),
                 sorted(target.ran),
-                "the fourth method must be reached automatically — proving a class can grow the "
+                "the added method must be reached automatically — proving a class can grow the "
                         + "set of things it validates with no change to the sweep itself");
     }
 
@@ -297,16 +251,16 @@ class FleetConfigValidateAllTest {
                   port: 8765
                 """, "auth.mode: token");
 
-        // validateLeadTabPrefixes: a fleet-wide tabLabel that starts with a lead's own tabPrefix.
+        // validateLeadTabPrefixes: a fleet-wide tabLabel that equals a lead tab.
         assertValidateAllRefuses(dir, "lead-tab-prefixes.yaml", """
                 bind:
                   host: 127.0.0.1
                   port: 8765
                 fleet:
-                  tabLabel: "lead: {role} {profile}"
+                  tabLabel: "alpha"
                   leaders:
                     opus:
-                      tab: "lead: opus"
+                      tab: "alpha"
                 """, "fleet.tabLabel");
 
         // validateSubscriptionProfiles: subscription: true with env: reseating ANTHROPIC_BASE_URL.

scripts/config-edit.sh

@@ -580,6 +580,12 @@ install_candidate() {
 
 # -------------------------------------------------------------------------------- the report path
 #
+# Masks basic-auth userinfo (scheme://user:pass@host) in a daemon verdict line before it reaches
+# the terminal.
+mask_verdict_userinfo() {
+  printf '%s\n' "$1" | sed -E 's#://[^@/[:space:]]*@#://<redacted>@#g'
+}
+
 # Prints the literal command the operator (or a test) can run to restore the backup by hand — the
 # absolute path to THIS script plus the overrides actually in force, so it works from any cwd.
 restore_command_line() {
@@ -599,8 +605,8 @@ restore_and_confirm() {
   ok "restored from $backup"
   if wait_for_verdict "$LOG" "$mark2" "$WAIT_SECONDS"; then
     case "$VERDICT_KIND" in
-      refused) warn "the RESTORE was also refused by the daemon: $VERDICT_LINE" ;;
-      *)       ok "restore confirmed: $VERDICT_LINE" ;;
+      refused) warn "the RESTORE was also refused by the daemon: $(mask_verdict_userinfo "$VERDICT_LINE")" ;;
+      *)       ok "restore confirmed: $(mask_verdict_userinfo "$VERDICT_LINE")" ;;
     esac
   else
     warn "the restore is on disk, but no confirming verdict line appeared within ${WAIT_SECONDS}s"
@@ -616,7 +622,7 @@ report_outcome() {
 
   say "waiting for the daemon's verdict (up to ${WAIT_SECONDS}s)"
   if wait_for_verdict "$LOG" "$mark" "$WAIT_SECONDS"; then
-    kind="$VERDICT_KIND"; line="$VERDICT_LINE"
+    kind="$VERDICT_KIND"; line="$(mask_verdict_userinfo "$VERDICT_LINE")"
   else
     kind="none"
   fi
@@ -673,7 +679,7 @@ check_mode() {
   local verdict
   verdict="$(last_verdict_line "$LOG")"
   if [ -n "$verdict" ]; then
-    ok "last verdict in log: $verdict"
+    ok "last verdict in log: $(mask_verdict_userinfo "$verdict")"
   else
     warn "no reload verdict line found in $LOG"
   fi

scripts/test-config-edit.sh

@@ -629,6 +629,65 @@ test_refusal_shape_from_parse_failure_wording_is_recognised() {
   assert_equals 4 "$RUN_RC" "the parse-failure refusal shape must also exit 4, not be read as silence"
 }
 
+# A verdict line carrying a credentialed URI has its userinfo masked, with a positive control
+# proving the rest of the line still reaches the output unchanged.
+test_verdict_userinfo_is_masked_with_positive_control() {
+  local dir
+  dir="$(new_fixture)"
+
+  start_run "$dir" 5 --set '.profiles.sonnet.weight=4'
+  sleep 1
+  printf 'config reload from %s refused, keeping the running config: refusing to start: malformed pattern — profiles.local.errorPattern ("amqp://user:hunter2@host/vhost"): Unclosed character class near index 8\n' \
+    "$dir/fleetd.yaml" >> "$dir/fleetd.out"
+  collect_run "$dir"
+
+  assert_equals 4 "$RUN_RC" "refusal-with-userinfo exit code"
+  assert_not_contains "user:hunter2" "$RUN_OUTPUT" "the userinfo must never reach the output"
+  assert_contains "amqp://<redacted>@host/vhost" "$RUN_OUTPUT" \
+    "the userinfo must be MASKED, not deleted — the rest of the quoted value must survive"
+  # Positive control: the diagnostic prose on both sides of the userinfo must still reach the
+  # output. Without this, a mutant that drops the whole verdict line would pass identically.
+  assert_contains "malformed pattern" "$RUN_OUTPUT" "prose BEFORE the userinfo must still reach the output"
+  assert_contains "Unclosed character class near index 8" "$RUN_OUTPUT" \
+    "prose AFTER the userinfo must still reach the output"
+}
+
+# An ordinary refusal line quotes the offending pattern, not a credential, and must survive byte
+# for byte: the rewrite is scoped to userinfo only, and the quoted pattern is the detail an
+# operator needs to fix the refusal.
+test_ordinary_refusal_line_passes_through_unchanged() {
+  local dir real_line
+  dir="$(new_fixture)"
+  real_line="config reload from $dir/fleetd.yaml refused, keeping the running config: refusing to start: malformed pattern — profiles.local.errorPattern (\"[unclosed\"): Unclosed character class near index 8"
+
+  start_run "$dir" 5 --set '.profiles.sonnet.weight=4'
+  sleep 1
+  printf '%s\n' "$real_line" >> "$dir/fleetd.out"
+  collect_run "$dir"
+
+  assert_equals 4 "$RUN_RC" "ordinary refusal exit code"
+  assert_contains "$real_line" "$RUN_OUTPUT" \
+    "an ordinary refusal with no userinfo must pass through byte for byte, unchanged"
+}
+
+# A verdict line can hold a URI with NO userinfo and a later, unrelated @ further on in the same
+# line (an email address in diagnostic prose, for example). The rewrite must stop at the end of
+# the URI and must not treat the later @ as a second userinfo delimiter.
+test_uri_without_userinfo_survives_a_later_at_sign() {
+  local dir real_line
+  dir="$(new_fixture)"
+  real_line="config reload from $dir/fleetd.yaml refused, keeping the running config: broker.uri amqp://broker.local/vhost unreachable, contact ops@example.com"
+
+  start_run "$dir" 5 --set '.profiles.sonnet.weight=4'
+  sleep 1
+  printf '%s\n' "$real_line" >> "$dir/fleetd.out"
+  collect_run "$dir"
+
+  assert_equals 4 "$RUN_RC" "no-userinfo-with-later-at-sign exit code"
+  assert_contains "$real_line" "$RUN_OUTPUT" \
+    "a URI with no userinfo plus a later @ in the same line must pass through byte for byte"
+}
+
 # --set runs yq over the whole candidate. It warns when that changes more lines than the requested
 # pairs, but a simple file with only the intended changed line must stay quiet.
 new_fixture_reformat_sensitive() {
@@ -720,6 +779,12 @@ echo "== extra: --check is read-only and always exits 0 =="
 test_check_is_read_only_and_exits_zero
 echo "== extra: the parse-failure refusal shape is also recognised =="
 test_refusal_shape_from_parse_failure_wording_is_recognised
+echo "== verdict-redaction criteria 2+3: verdict userinfo is masked, rest of line survives =="
+test_verdict_userinfo_is_masked_with_positive_control
+echo "== verdict-redaction criterion 4: an ordinary refusal passes through unchanged =="
+test_ordinary_refusal_line_passes_through_unchanged
+echo "== fleetd #638: a URI with no userinfo survives a later @ in the same line =="
+test_uri_without_userinfo_survives_a_later_at_sign
 echo "== acceptance criterion 17: --set warns about yq formatting churn =="
 test_set_warns_when_yq_reformats_extra_lines
 echo "== acceptance criterion 18: --set stays quiet without formatting churn =="