feat(terminology): prose sweep tool and custodian workplan cleanup (CUST-WP-0055 T04)

Add sweep_workstream_prose.py for agent-guidance files, sweep active workplan
prose in-repo, tighten scan allowlist exclusions, and update ADR-001 closure
protocol to workplan-first terminology.

workplans/CUST-WP-0010-workstream-lifecycle-docs.md

@@ -1,7 +1,7 @@
 ---
 id: CUST-WP-0010
 type: workplan
-title: Workstream Lifecycle Documentation
+title: Workplan Lifecycle Documentation
 domain: infotech
 status: completed
 owner: custodian
@@ -11,11 +11,11 @@ created: 2026-03-03
 updated: 2026-03-03
 ---
 
-# CUST-WP-0010 — Workstream Lifecycle Documentation
+# CUST-WP-0010 — Workplan Lifecycle Documentation
 
 ## Purpose
 
-The dashboard "Workstreams by Domain" chart exposes seven computed states
+The dashboard "Workplans by Domain" chart exposes seven computed states
 (active, accepted, finished, blocked, stalled, oldies + time-based modes).
 These need to be documented so that Bernd and the custodian share a common
 vocabulary, and so the "accepted" quality-gate pattern is clearly understood
@@ -46,7 +46,7 @@ priority: high
 state_hub_task_id: "95e5810d-947a-4039-b017-9bee85cf4f48"
 ```
 
-### Step 2: Update workstreams reference
+### Step 2: Update workplans reference
 ```task
 id: CUST-WP-0010-T2
 title: Update docs/workstreams.md status table
@@ -68,7 +68,7 @@ state_hub_task_id: "4cef0841-5324-4fbc-a44b-ad8520f77c9f"
 
 - "accepted" maps to DB `status = "completed"` — the name change reflects intent
 - The lifecycle is linear: active → finished (task-derived) → accepted (human+custodian gate)
-- Attention signals (blocked, stalled, oldies) are orthogonal — a workstream can be
+- Attention signals (blocked, stalled, oldies) are orthogonal — a workplan can be
   active AND stalled at the same time
 - The custodian uses the "finished but not accepted" gap as the trigger to run
   quality checks and create follow-up tasks before signing off