feat(state-hub): implement v0.5 — dynamic domains & multi-repo

Replaces the hardcoded 6-domain PostgreSQL ENUM with a first-class
`domains` DB table, and adds a `managed_repos` table for multi-repo
support per domain.

P1 — Domain as a DB entity:
- Migration b1c2d3e4f5a6: creates `domains` table, migrates topics.domain
  ENUM column to domain_id FK, drops the domain ENUM type
- Domain ORM model (api/models/domain.py) + Pydantic schemas
- Domain API router: GET/POST /domains/, GET/PATCH /domains/{slug}/,
  rename and archive endpoints with EP/TD cascade on rename
- Topic model updated: domain_id FK + @property domain_slug for
  backwards-compatible JSON serialization (field renamed domain → domain_slug)
- TopicCreate/TopicRead updated; seed.py rewritten to use FK lookup

P2 — Multi-repo support:
- ManagedRepo ORM model (api/models/managed_repo.py) + schemas
- Repo API router: GET/POST /repos/, GET/PATCH /repos/{slug}/, archive
- Makefile: add-domain, rename-domain, add-repo, list-repos targets
- register_project.sh: verify domain via /domains/ API + POST /repos/

P3 — MCP tools & live validation:
- 6 new MCP tools: list_domains, create_domain, rename_domain,
  archive_domain, list_domain_repos, register_repo
- EP/TD routers: replace hardcoded VALID_DOMAINS set with per-request
  DB lookup — returns 422 with list of valid slugs on unknown domain
- State summary: adds domains: list[DomainSummary] (slug, name,
  repo_count, active_workstream_count, ep_count, td_count)
- TOOLS.md updated with domain management section

P4 — Dashboard:
- New domains.md page with KPI row + domain cards + repo lists
- domains.json.py + repos.json.py data loaders
- Domains page added to observablehq.config.js nav
- workstreams.md, extensions.md, techdept.md: domain_slug fix +
  dynamic domain list loaded from /domains/ API (no longer hardcoded)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

mcp_server/server.py

@@ -630,6 +630,124 @@ def update_td_status(td_uuid: str, status: str) -> str:
     return json.dumps(td, indent=2)
 
 
+# ---------------------------------------------------------------------------
+# Domain lifecycle + repo registration tools (v0.5)
+# ---------------------------------------------------------------------------
+
+@mcp.tool()
+def list_domains(status: str = "active") -> str:
+    """List all registered domains.
+
+    Args:
+        status: active | archived | all (default: active)
+    """
+    return json.dumps(_get("/domains", {"status": status}), indent=2)
+
+
+@mcp.tool()
+def create_domain(slug: str, name: str, description: str | None = None) -> str:
+    """Create a new domain.
+
+    Args:
+        slug: URL-friendly identifier (lowercase, underscored), e.g. 'my_project'
+        name: Human-readable display name
+        description: optional longer description
+    """
+    domain = _post("/domains", {"slug": slug, "name": name, "description": description})
+    _post("/progress", {
+        "event_type": "milestone",
+        "summary": f"Domain created: {slug} ({name})",
+        "author": "custodian",
+        "detail": {"slug": slug, "name": name},
+    })
+    return json.dumps(domain, indent=2)
+
+
+@mcp.tool()
+def rename_domain(slug: str, new_slug: str, new_name: str) -> str:
+    """Rename a domain — cascades to EP/TD string columns.
+
+    Args:
+        slug: Current domain slug
+        new_slug: New URL-friendly identifier
+        new_name: New human-readable display name
+    """
+    domain = _patch(f"/domains/{slug}/rename", {"new_slug": new_slug, "new_name": new_name})
+    _post("/progress", {
+        "event_type": "milestone",
+        "summary": f"Domain renamed: {slug} → {new_slug} ({new_name})",
+        "author": "custodian",
+        "detail": {"old_slug": slug, "new_slug": new_slug, "new_name": new_name},
+    })
+    return json.dumps(domain, indent=2)
+
+
+@mcp.tool()
+def archive_domain(slug: str) -> str:
+    """Archive a domain (soft-delete). Fails if active topics exist.
+
+    Args:
+        slug: Domain slug to archive
+    """
+    domain = _patch(f"/domains/{slug}/archive", {})
+    _post("/progress", {
+        "event_type": "note",
+        "summary": f"Domain archived: {slug}",
+        "author": "custodian",
+        "detail": {"slug": slug},
+    })
+    return json.dumps(domain, indent=2)
+
+
+@mcp.tool()
+def list_domain_repos(domain_slug: str) -> str:
+    """List all repositories registered under a domain.
+
+    Args:
+        domain_slug: Domain slug to filter by
+    """
+    return json.dumps(_get("/repos", {"domain": domain_slug}), indent=2)
+
+
+@mcp.tool()
+def register_repo(
+    domain_slug: str,
+    name: str,
+    slug: str | None = None,
+    local_path: str | None = None,
+    remote_url: str | None = None,
+    description: str | None = None,
+) -> str:
+    """Register a git repository under a domain.
+
+    Args:
+        domain_slug: Domain slug (must already exist)
+        name: Human-readable repository name
+        slug: URL-friendly identifier (auto-generated from name if omitted)
+        local_path: Absolute local filesystem path to the repo
+        remote_url: Remote git URL (Gitea, GitHub, etc.)
+        description: optional description
+    """
+    import re as _re
+    if not slug:
+        slug = _re.sub(r"[^a-z0-9]+", "-", name.lower()).strip("-")
+    repo = _post("/repos", {
+        "domain_slug": domain_slug,
+        "slug": slug,
+        "name": name,
+        "local_path": local_path,
+        "remote_url": remote_url,
+        "description": description,
+    })
+    _post("/progress", {
+        "event_type": "milestone",
+        "summary": f"Repo registered: {name} under domain '{domain_slug}'",
+        "author": "custodian",
+        "detail": {"slug": slug, "domain_slug": domain_slug, "local_path": local_path, "remote_url": remote_url},
+    })
+    return json.dumps(repo, indent=2)
+
+
 # ---------------------------------------------------------------------------
 # ADR-001 compliance validation
 # ---------------------------------------------------------------------------