feat(standards): MR-based tag strategy + repository inventory (registry://repos)

Versioning standard now documents the MR flow: bump pyproject.toml/VERSION and promote CHANGELOG in the MR (referencing the version/tag, not a commit id), merge/squash, then tag the resulting commit. Adds the agent-assisted tagging procedure (wait for the go-ahead, find the version-bump commit, tag only it, ask the user to push) to both the reference page and the releasing wiki runbook. Adds the repo inventory (src/repos.json -> mcp/repos.json), the registry://repos resource + list_repos tool, the 15_repository_inventory lib page, and two MCP prompts: compliance (remediate repos) and release (agent tagging).

build.py

@@ -490,6 +490,39 @@ def build_release_templates(folder: Path, dry_run: bool = False) -> None:
           f"({len(manifest['components'])} components)")
 
 
+# ── Repository inventory bundle ───────────────────────────────────────────────
+
+
+def build_repos(folder: Path, dry_run: bool = False) -> None:
+    """Publish ``folder/src/repos.json`` as ``<name>/mcp/repos.json``.
+
+    The repository inventory (name, type, version source, Drone shape) is a
+    single hand-authored JSON file, surfaced to agents through the
+    ``registry://repos`` resource and the ``list_repos`` tool. See standards
+    "15_repository_inventory".
+
+    Args:
+        folder (Path): The hub folder owning ``src/repos.json``.
+        dry_run (bool): Print the plan without executing.
+    """
+    name = folder.name
+    src = folder / "src" / "repos.json"
+    if not src.is_file():
+        return
+    out = folder / "mcp" / "repos.json"
+    if dry_run:
+        print(f"[REP]  {name}  {src.relative_to(ROOT)} -> {out.relative_to(ROOT)}")
+        return
+
+    data = json.loads(src.read_text(encoding="utf-8"))
+    out.parent.mkdir(parents=True, exist_ok=True)
+    out.write_text(
+        json.dumps(data, indent=2, ensure_ascii=False), encoding="utf-8"
+    )
+    print(f"[REP]  {name}  repo inventory written to {out.relative_to(ROOT)} "
+          f"({len(data.get('repos', []))} repos)")
+
+
 # ── CLI ──────────────────────────────────────────────────────────────────────
 
 
@@ -511,6 +544,7 @@ def main() -> None:
         build_templates(folder, dry_run=args.dry_run)
         build_drone_templates(folder, dry_run=args.dry_run)
         build_release_templates(folder, dry_run=args.dry_run)
+        build_repos(folder, dry_run=args.dry_run)
         build_html(folder, dry_run=args.dry_run)