fleetd #661: add the pane-placement case to the validateAll reachability enumeration

validateAllReachesEveryOneOfTodaysSixValidators only covered six of
the eight real validators; the new validator was reachability-tested
only from FleetConfigTest, in a different file from the one whose job
is to enumerate every validateAll-reachability case.

Add the pane-placement case to the enumeration, rename the method to
drop the hardcoded count (validateAllReachesEveryOneOfTodaysRealValidators),
and correct the surrounding claims to say seven of eight, naming
validateLeadRollover as the one case still missing (fleetd #668, not
fixed here).

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

@@ -42,12 +42,13 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
  *       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 #validateAllReachesEveryOneOfTodaysSixValidators()} proves {@link
+ *   <li>{@link #validateAllReachesEveryOneOfTodaysRealValidators()} proves {@link
  *       FleetConfig#validateAll()} itself is wired to that same generic mechanism and genuinely
- *       reaches each of today's six real validators — reusing the exact minimal failing
+ *       reaches seven of today's eight real validators — reusing the exact minimal failing
  *       configurations {@code FleetConfigTest} already established for each one directly, so a
- *       single call to {@code validateAll()} is shown to reproduce every one of those six
- *       failures.</li>
+ *       single call to {@code validateAll()} is shown to reproduce every one of those seven
+ *       failures. The eighth, {@link FleetConfig#validateLeadRollover()}, has no case here yet —
+ *       a pre-existing gap tracked as fleetd #668.</li>
  * </ol>
  *
  * <p>Together with the direct-{@code Fleetd.main}-invocation tests in {@code
@@ -209,7 +210,7 @@ class FleetConfigValidateAllTest {
                         + "name) must all be skipped");
     }
 
-    // ── Claim 2: FleetConfig.validateAll() is wired to that mechanism and reaches all six today ──
+    // ── Claim 2: FleetConfig.validateAll() is wired to that mechanism and reaches seven of eight today ──
 
     /**
      * Reflectively enumerates {@link FleetConfig}'s own public, no-arg, void {@code validateXxx()}
@@ -264,14 +265,17 @@ class FleetConfigValidateAllTest {
     }
 
     /**
-     * The heart of claim 2: for each of today's six real validators, a minimal file that fails
+     * The heart of claim 2: for seven of today's eight real validators, a minimal file that fails
      * ONLY that one — the exact fixtures {@code FleetConfigTest} uses to test each validator
      * directly — must also fail through {@link FleetConfig#validateAll()}. If a future edit to
-     * {@code validateAll()} silently dropped one validator from the sweep (e.g. a typo'd name
-     * filter), exactly one of these six would start passing when it must not.
+     * {@code validateAll()} silently dropped one of these seven from the sweep (e.g. a typo'd name
+     * filter), exactly one of them would start passing when it must not.
+     *
+     * <p>The eighth, {@link FleetConfig#validateLeadRollover()}, has no case here — a pre-existing
+     * gap tracked as fleetd #668, not fixed by this change.
      */
     @Test
-    void validateAllReachesEveryOneOfTodaysSixValidators(@TempDir Path dir) throws Exception {
+    void validateAllReachesEveryOneOfTodaysRealValidators(@TempDir Path dir) throws Exception {
         // validateAuthExposure: a non-loopback bind without token mode.
         assertValidateAllRefuses(dir, "auth-exposure.yaml", """
                 bind:
@@ -344,6 +348,20 @@ class FleetConfigValidateAllTest {
                   allow:
                     - model: claude-sonnet-5
                 """, "rogue");
+
+        // validatePanePlacementAgainstLeadTabs: a pane-placed profile while a lead names a tab.
+        assertValidateAllRefuses(dir, "pane-placement.yaml", """
+                bind:
+                  host: 127.0.0.1
+                  port: 8765
+                profiles:
+                  gx10:
+                    placement: pane
+                fleet:
+                  leaders:
+                    opus:
+                      tab: "lead: opus"
+                """, "gx10");
     }
 
     private static void assertValidateAllRefuses(Path dir, String fileName, String yaml,