feat(terminology): add fleet scan allowlist and prose gate (CUST-WP-0055 T08)

Extend scan_workstream_terminology.py with allowlist loading, --apply-allowlist,
and --check-prose-gate for regression detection. Commit the T08 exclusion
config and unit tests; mark T01/T03/T08 done and activate the fleet workplan.

tools/scan_workstream_allowlist.yaml

@@ -0,0 +1,60 @@
+# Fleet scan exclusions for CUST-WP-0055 T08 prose gate.
+# Paths are relative to each repo root. Globs use fnmatch (*, ?).
+
+version: 1
+
+global:
+  path_prefixes:
+    - workplans/archived/
+    - memory/
+
+per_repo:
+  the-custodian:
+    path_prefixes:
+      - canon/standards/workplan-terminology-fleet_v0.1.md
+      - tools/scan_workstream_terminology.py
+      - tools/scan_workstream_allowlist.yaml
+      - docs/evidence/workstream-terminology-baseline-20260708.json
+      - workplans/CUST-WP-0055-workplan-terminology-fleet-refactor.md
+      - workplans/CUST-WP-0010-workstream-lifecycle-docs.md
+      - wiki/
+      - roadmap/
+
+  state-hub:
+    path_prefixes:
+      - docs/workplan-terminology-transition.md
+      - docs/workplan-terminology-legacy-retirement-backlog.md
+      - docs/nats-event-subjects.md
+      - api/routers/workstreams.py
+      - api/routers/workstream_dependencies.py
+      - api/routers/legacy_meter.py
+      - api/services/legacy_meter.py
+      - api/models/legacy_meter.py
+      - mcp_server/
+      - migrations/
+      - tests/test_legacy_meter.py
+      - tests/test_routers_core.py
+      - custodian_cli.py
+      - scripts/consistency_check.py
+    path_globs:
+      - workplans/STATE-WP-0054*
+      - workplans/STATE-WP-0069*
+
+  activity-core:
+    path_globs:
+      - event-types/org.workstream.completed.md
+      - event-types/org.statehub.workstream.completed.md
+
+  agentic-resources:
+    exclude_repo: true
+
+# Wire-compat pattern buckets — always excluded from prose gate counts.
+patterns_always_allowed:
+  - frontmatter:state_hub_workstream_id
+  - api:workstream_id
+  - mcp:create_workstream
+  - mcp:update_workstream
+  - mcp:list_workstreams
+  - api:open_workstreams
+  - path:workstreams/
+  - term:workstreams