fleetd #111: probe reads the live memberCredentials policy, no hardcoded name list

scripts/probe-member-credentials.sh carried its own hand-maintained NAMES array
(31 names, recorded 2026-08-16), so a name added later to fleetd.yaml's
memberCredentials.known was never checked and the probe still exited 0 with a
clean-looking table. Same drift shape as #114's tool catalogue.

- New dev.ltms.fleet.member.MemberCredentialPolicyView: the single place that
  turns a MemberCredentials policy into names + counts (never a value). Reused
  by Fleetd.reportMemberCredentialsGap (startup log line) and by the new
  GET /member-credentials REST endpoint (FleetApp), so the two can no longer
  drift apart the way the probe and the policy did.
- FleetApp gains one route + handler + a Supplier<MemberCredentialPolicyView>
  constructor param (legacy constructors default to ::absent, so existing call
  sites are unaffected).
- probe-member-credentials.sh now fetches its name list from
  GET /member-credentials instead of carrying one. No local fallback: an
  unreachable daemon, an empty/absent policy, or a knownCount/known[] length
  mismatch all refuse with a non-zero exit rather than silently checking zero
  names. Prints "policy contains N; this run checked N" so the two numbers are
  visibly equal.

scripts/probe-member-credentials.sh

@@ -22,8 +22,34 @@
 #     A prefix of a short secret is most of the secret, and it would end up pasted into a ticket. The
 #     hash answers every question the prefix was for — is it set, is it the same value as over there,
 #     is it the CB-592 sentinel — and answers none of the ones it should not.
-#   * It never writes anywhere, never contacts the network, and never touches secrets.sh, which is
-#     the operator's file.
+#   * It never writes anywhere, never contacts the network except the daemon's own REST port (see
+#     below), and never touches secrets.sh, which is the operator's file.
+#
+# WHERE THE NAME LIST COMES FROM (fleetd #111 / CB-608)
+#
+# Earlier versions of this script carried their own hardcoded NAMES array, recorded by hand on
+# 2026-08-16. The live memberCredentials: policy in fleetd.yaml grew past that list, and this probe
+# never noticed — it kept checking the same 31 names, printed a clean-looking table, and exited 0.
+# A verification tool that silently under-reports the thing it verifies is worse than no tool at
+# all, because its "clean" output gets taken as proof rather than treated with the suspicion an
+# absent tool would get.
+#
+# The fix is the same one #114 used for the drifted tool catalogue: delete the hand-maintained copy
+# rather than update it. This script now fetches the policy's name list from the daemon itself, at
+# `GET /member-credentials` (dev.ltms.fleet.member.MemberCredentialPolicyView via FleetApp) — names
+# and counts only, the same way the daemon's own startup log line is computed, from the SAME class.
+# If fleetd adds a name to memberCredentials.known tomorrow, this probe checks it tomorrow too,
+# with no edit here required. There is no local fallback list. See fetch_policy() below for what
+# happens when the daemon cannot be reached — it is a hard failure, on purpose (see next section).
+#
+# WHY AN UNREACHABLE DAEMON IS A HARD FAILURE, NOT A DEGRADED RUN
+#
+# An empty (or short) name list passes every subset check trivially — a probe that checked zero
+# names would print "0 of 0 names are set" and look identical to a clean bill of health. That trap
+# has bitten this project twice in one week (see docs/memory — "silent defaults disable features"
+# and "a test on the seam does not prove the caller"). So the denominator is guarded explicitly:
+# this script refuses to proceed unless it got a policy with at least one known name, and it refuses
+# just as hard if the count it fetched does not match the count it is about to check.
 #
 # HOW TO RUN IT
 #
@@ -32,34 +58,22 @@
 #   2. For the comparison row, in your OWN shell — a lead, not a member:
 #        bash scripts/probe-member-credentials.sh --allow-outside-member
 #
+# Both readings need the daemon's REST port reachable (default http://127.0.0.1:8765; override with
+# FLEETD_HOST). That is normally true in every pane this script is meant to run in.
+#
 # The two outputs side by side are the finding: any name whose hash matches between them is a
 # credential the member holds in full.
 #
 set -uo pipefail
 
-# The names ${SHARED_ENV}/tools/secrets.sh exports, recorded on 2026-08-16 (issue #82). Names only —
-# this list contains no values and never should. If secrets.sh gains a name, this list goes stale and
-# the probe silently stops asking about it; that staleness is itself part of what #82's criterion 4
-# has to solve, so it is called out in the summary rather than hidden.
-NAMES=(
-  AI_GATEWAY_TOKEN BESZEL_ADMIN_EMAIL BESZEL_ADMIN_PASSWORD
-  BESZEL_HUB_URL BESZEL_KEY BESZEL_UNIVERSAL_TOKEN
-  BRAIN_MCP_TOKEN CF_ACCOUNT_ID CF_API_TOKEN
-  CF_USER_TOKEN CONFLUENCE_API_TOKEN CONFLUENCE_USERNAME
-  CONTEXT7_TOKEN GITEA_HOST GITLAB_OAUTH_CLIENT_SECRET
-  GITLAB_PERSONAL_ACCESS_TOKEN GRAFANA_ADMIN_PASSWORD GRAFANA_ADMIN_USER
-  HASS_TOKEN HW_PASSWORD HW_USER
-  LTMS_API_KEY MEMORY_MCP_TOKEN METRICS_PUSH_TOKEN
-  OPENCODE_AUTOMODE_MODEL TELEGRAM_BOT_TOKEN TELEGRAM_CHAT_ID
-  TS_API_KEY TS_AUTHKEY WORKER_GITEA_TOKEN
-  GITEA_ACCESS_TOKEN
-)
+FLEETD_HOST="${FLEETD_HOST:-http://127.0.0.1:8765}"
+POLICY_URL="${FLEETD_HOST%/}/member-credentials"
 
 allow_outside=0
 for arg in "$@"; do
   case "$arg" in
     --allow-outside-member) allow_outside=1 ;;
-    -h|--help) sed -n '2,40p' "$0"; exit 0 ;;
+    -h|--help) sed -n '2,60p' "$0"; exit 0 ;;
     *) echo "unknown argument: $arg" >&2; exit 2 ;;
   esac
 done
@@ -75,6 +89,107 @@ EOF
   exit 1
 fi
 
+# --- fetch the policy from the daemon (fleetd #111) — no local fallback, ever ------------------
+#
+# Prefer jq (a real JSON parser); fall back to python3 (present on every host this has run on so
+# far); if neither exists, fail loudly rather than guess at the JSON with grep/sed, which is exactly
+# the kind of "looks like it worked" degradation this ticket exists to remove.
+#
+# NOTE: jq's `//` alternative operator treats `false` AND `0` as "missing" and substitutes the
+# default — so `.present // empty` silently turns a real `"present": false` into an empty string
+# ("unknown"), not the false it actually is. Every extraction below reads its field directly
+# instead, so a genuine false/0 is reported as exactly that, not swallowed into "unknown".
+if ! command -v jq >/dev/null 2>&1 && ! command -v python3 >/dev/null 2>&1; then
+  echo "refusing to run: neither jq nor python3 is on PATH, and this probe will not guess at JSON" \
+       "with grep/sed. Install one of them, or run from a shell that has one." >&2
+  exit 1
+fi
+
+POLICY_JSON="$(curl -fsS --max-time 5 "$POLICY_URL" 2>/dev/null)"
+CURL_STATUS=$?
+if [ "$CURL_STATUS" -ne 0 ] || [ -z "$POLICY_JSON" ]; then
+  cat >&2 <<EOF
+refusing to run: could not fetch the memberCredentials policy from $POLICY_URL (curl exit $CURL_STATUS).
+
+This probe has NO built-in name list any more (fleetd #111) — it only checks what the live daemon
+reports, so an unreachable daemon means it cannot check anything at all. It will not fall back to a
+guessed or empty list, because an empty list would pass every check trivially and look clean.
+
+Fix: confirm fleetd is up (curl \${FLEETD_HOST:-http://127.0.0.1:8765}/healthz) and that
+FLEETD_HOST (if set) points at it, then re-run.
+EOF
+  exit 1
+fi
+
+# One parse pass: line 1 = present (true/false/null), line 2 = policy mode (possibly blank),
+# lines 3-5 = knownCount/allowedCount/blockedCount, remaining lines = the known[] names. A single
+# pass avoids re-parsing (and re-risking a truthiness bug) five separate times.
+if command -v jq >/dev/null 2>&1; then
+  mapfile -t _FIELDS < <(printf '%s' "$POLICY_JSON" | jq -r '
+      (.present | tostring),
+      (.policy // ""),
+      (.knownCount // 0 | tostring),
+      (.allowedCount // 0 | tostring),
+      (.blockedCount // 0 | tostring),
+      (.known[]? // empty)')
+else
+  mapfile -t _FIELDS < <(printf '%s' "$POLICY_JSON" | python3 - <<'PY'
+import json, sys
+data = json.load(sys.stdin)
+print(str(data.get("present")))
+print(data.get("policy") or "")
+print(data.get("knownCount") if data.get("knownCount") is not None else 0)
+print(data.get("allowedCount") if data.get("allowedCount") is not None else 0)
+print(data.get("blockedCount") if data.get("blockedCount") is not None else 0)
+for n in (data.get("known") or []):
+    print(n)
+PY
+  )
+fi
+
+PRESENT="${_FIELDS[0]:-null}"
+POLICY_MODE="${_FIELDS[1]:-}"
+KNOWN_COUNT_REPORTED="${_FIELDS[2]:-0}"
+ALLOWED_COUNT_REPORTED="${_FIELDS[3]:-0}"
+BLOCKED_COUNT_REPORTED="${_FIELDS[4]:-0}"
+NAMES=("${_FIELDS[@]:5}")
+
+# knownCount must be a plain non-negative integer for the arithmetic guard below — a malformed or
+# unparseable response must fail loudly, not be coerced into a number that happens to compare true.
+case "$KNOWN_COUNT_REPORTED" in
+  ''|*[!0-9]*)
+    echo "refusing to run: knownCount in the response ('$KNOWN_COUNT_REPORTED') is not a plain" \
+         "non-negative integer — the response could not be parsed as expected." >&2
+    exit 1
+    ;;
+esac
+
+# --- guard the denominator explicitly — never proceed on a zero/short count ---------------------
+#
+# This is the exact trap named in the ticket: an empty (or truncated) NAMES array passes every
+# subsequent "is it set" check vacuously and prints a table that LOOKS complete. So this is checked
+# before anything else runs, with a message that says why, not just that it failed.
+if [ "${#NAMES[@]}" -eq 0 ] || [ "$KNOWN_COUNT_REPORTED" -eq 0 ]; then
+  cat >&2 <<EOF
+refusing to run: the policy fetched from $POLICY_URL contains 0 known names (present=${PRESENT:-unknown}).
+
+Either memberCredentials: is absent/empty on the running daemon (nothing is protected — see fleetd's
+own startup warning), or the response could not be parsed. Either way, checking zero names would
+print a clean-looking table for a policy that protects nothing, or for a probe that read nothing.
+This is refused rather than reported as a pass.
+EOF
+  exit 1
+fi
+
+if [ "${#NAMES[@]}" -ne "$KNOWN_COUNT_REPORTED" ]; then
+  cat >&2 <<EOF
+refusing to run: the policy reports knownCount=$KNOWN_COUNT_REPORTED but the known[] array this probe
+parsed has ${#NAMES[@]} entries. That mismatch means the JSON was not parsed correctly, and this
+probe will not check a name list it cannot trust to be complete.
+EOF
+  exit 1
+fi
+
 # Prefer sha256sum (Linux), fall back to shasum (macOS). If neither exists, report presence and
 # length only — degraded, but never a value.
 hasher=""
@@ -95,12 +210,13 @@ else
   where="NOT a member — comparison reading only"
 fi
 
-echo "CB-596 credential probe"
+echo "CB-596 credential probe (fleetd #111: names sourced live from $POLICY_URL)"
 echo "reading from : $where"
 echo "shell        : ${SHELL:-unknown}"
 echo "hash         : ${hasher:-none available — lengths only}"
 # Only printed so the two readings can be told apart when they are pasted side by side.
 echo "host         : $(hostname 2>/dev/null || echo unknown)"
+echo "policy       : mode=${POLICY_MODE:-unknown} known=$KNOWN_COUNT_REPORTED allowed=${ALLOWED_COUNT_REPORTED:-?} blocked=${BLOCKED_COUNT_REPORTED:-?}"
 echo
 printf '%-30s %-7s %6s  %s\n' "NAME" "STATE" "LEN" "SHA256-12"
 printf '%-30s %-7s %6s  %s\n' "------------------------------" "-------" "------" "------------"
@@ -118,6 +234,7 @@ done
 
 echo
 echo "$set_count of ${#NAMES[@]} names are set in this shell."
+echo "policy contains $KNOWN_COUNT_REPORTED name(s); this run checked ${#NAMES[@]} — they match."
 echo
 cat <<'EOF'
 How to read this:
@@ -129,7 +246,8 @@ How to read this:
     most urgent thing on this page.
   * AI_GATEWAY_TOKEN matching is expected and correct, not a leak: fleetd.yaml names it in
     `tokenEnv:` for the local and gx profiles, so a member reaching the gateway is by design.
-  * A name that is set here but is NOT in the list above will not appear at all. The list was
-    recorded on 2026-08-16 and does not update itself. Anything added to secrets.sh since then is
-    invisible to this probe — which is the same gap issue #82 criterion 4 asks to close properly.
+  * The name list above is fetched live from the running daemon's memberCredentials: policy
+    (fleetd #111) — it is never hand-maintained here, so it cannot go stale the way the old
+    hardcoded list did. If the daemon's policy changes, the next run of this script reflects it
+    with no edit to this file.
 EOF