fix(api): normalize trailing slashes — no slash on param routes

Rule: trailing slash only on collection roots (/). Any route containing
a path parameter {…} uses no trailing slash. Applies across all routers,
scripts, Makefile, and tests. Fixes 307-redirect fragility on POST/PATCH
from naive clients (curl, Codex HTTP calls).

Also adds POST /repos/{slug}/sync — runs ADR-001 consistency check with
--fix via HTTP, so non-MCP agents (Codex) can self-service DB sync without
operator intervention.

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

scripts/consistency_check.py

@@ -1083,7 +1083,7 @@ def fix_repo(
             hostname = socket.gethostname()
             if (repo_record.get("host_paths") or {}).get(hostname) != repo_path:
                 result = _api_post(
-                    api_base, f"/repos/{repo_slug}/paths/",
+                    api_base, f"/repos/{repo_slug}/paths",
                     {"host": hostname, "path": repo_path},
                 )
                 if result and "_error" not in result:
@@ -1333,7 +1333,7 @@ def fix_repo(
     from datetime import timezone as _tz
     import datetime as _dt
     now_iso = _dt.datetime.now(_tz.utc).isoformat()
-    _api_patch(api_base, f"/repos/{repo_slug}/", {"last_state_synced_at": now_iso})
+    _api_patch(api_base, f"/repos/{repo_slug}", {"last_state_synced_at": now_iso})
 
     # Write the worker orientation brief (.custodian-brief.md)
     if repo_path: