feat(classification-spine): implement STATE-WP-0065 repo-anchored model

Replace the ad-hoc coordination-domain spine with the Repo Classification
Standard: 14 market domains, classification columns on managed_repos, and
workplans anchored by repo_id (topic_id optional).

- Add Alembic migration d8e9f0a1b2c3 with data backfill and workstream→workplan rename
- Add api/classification.py validation and register-from-classification tooling
- Expose workplan-first REST/MCP surface with legacy workstream aliases
- Add C-24 consistency rule and legacy domain frontmatter mapping
- Update dashboard repos page with category/capability/stake filters
- Update orientation docs; mark STATE-WP-0065 finished

tests/test_legacy_meter.py

@@ -17,8 +17,20 @@ async def _create_topic(client, domain_slug="legacy-domain", slug="legacy-topic"
     return r.json()
 
 
-async def _create_workplan(client, topic_id, slug="legacy-wp", title="Legacy WP"):
+async def _create_repo(client, domain_slug="legacy-domain", slug="legacy-repo"):
+    r = await client.post("/repos/", json={
+        "domain_slug": domain_slug,
+        "slug": slug,
+        "name": "Legacy Repo",
+    })
+    assert r.status_code == 201, r.text
+    return r.json()
+
+
+async def _create_workplan(client, topic_id, domain_slug="legacy-domain", slug="legacy-wp", title="Legacy WP"):
+    repo = await _create_repo(client, domain_slug=domain_slug, slug=f"{slug}-repo")
     r = await client.post("/workplans/", json={
+        "repo_id": repo["id"],
         "topic_id": topic_id,
         "slug": slug,
         "title": title,