Complete workplan state model cleanup

scripts/project_rules/agents-codex.template

@@ -82,7 +82,7 @@ curl -s -X PATCH "http://127.0.0.1:8000/tasks/<task_id>" \
 **Start:**
 1. `cat .custodian-brief.md` — domain goal and open workstreams (offline-safe)
 2. Check inbox: `GET /messages/?to_agent={REPO_SLUG}&unread_only=true`; mark read
-3. Scan workplans: `ls workplans/` — note `status: active` files and open tasks
+3. Scan workplans: `ls workplans/` — note `status: ready`, `active`, or `blocked` files and open tasks
 4. Check blocked tasks: `GET /tasks/?needs_human=true`
 
 **During work:**
@@ -108,7 +108,7 @@ read/cache/index layer that rebuilds from files.
 
 **File location:** `workplans/{WP_PREFIX}-NNNN-<slug>.md`
 
-**Archived location:** completed workplans may move to
+**Archived location:** finished workplans may move to
 `workplans/archived/YYMMDD-{WP_PREFIX}-NNNN-<slug>.md`. The `YYMMDD` prefix is
 the completion/archive date; the frontmatter `id` does not change.
 
@@ -126,7 +126,7 @@ type: workplan
 title: "..."
 domain: {DOMAIN}
 repo: {REPO_SLUG}
-status: active | done
+status: proposed | ready | active | blocked | backlog | finished | archived
 owner: codex
 topic_slug: ...
 created: "YYYY-MM-DD"
@@ -135,6 +135,10 @@ state_hub_workstream_id: "<uuid>"   # written by fix-consistency — do not edit
 ---
 ```
 
+Use `proposed` for a new draft, `ready` after review against current repo
+state, and `finished` after implementation. `stalled` and `needs_review` are
+derived health labels, not frontmatter statuses.
+
 **Task block format** (one per `##` section):
 
 ```