Normalize agent instructions and workplan frontmatter (STATE-WP-0067)

- Align agent files with on-disk workplan prefixes (infer from workplan ids)
- Set workplan domain to registered domain_slug; add topic_slug where applicable
- Repair frontmatter delimiter formatting; migrate legacy task status literals
- Regenerate AGENTS.md, CLAUDE.md, and .claude/rules from State Hub templates

.claude/rules/repo-identity.md

@@ -1,5 +1,5 @@
-**Purpose:** Django 6 + Tailwind + HTMX bid management app
+**Purpose:** Coulomb project repository (bootstrapped from repo-seed template)
 
-**Domain:** vergabe_teilnahme
-**Repo slug:** vergabe_teilnahme
-**Topic ID:** 7d4d3e35-312f-4723-bde9-ddb43799109e
+**Domain:** communication
+**Repo slug:** vergabe-teilnahme
+**Topic ID:** 36c7421b-c537-4723-bf75-42a3ebc6a1dc