feat: coord API — no-auth, DB softfail 503, agent tracking protocol

- coord routers: removed JWT auth requirement (internal-only endpoints)
- error_handler: SQLAlchemy OperationalError/DisconnectionError → 503
  with Retry-After: 30 header instead of 500
- /health: live DB probe (SELECT 1) instead of static response
- CLAUDE.md: "Live State Tracking" section with full agent protocol
  for all projects — session start, lock claim/release, component
  state updates, softfail + local queue catch-up
- COORDINATION_PROTOCOL.md: softfail/catch-up section + server-side
  503 behavior documented

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

api/routers/coord_locks.py

@@ -6,7 +6,6 @@ from fastapi import APIRouter, Depends, Query, status
 from sqlalchemy.orm import Session
 
 from api.database import get_db
-from api.middleware.auth import get_current_user
 from api.schemas.coord_session_lock import CoordSessionLockCreate, CoordSessionLockResponse
 from api.services import coord_lock_service
 
@@ -20,7 +19,6 @@ def list_active_locks(
     skip: int = Query(default=0, ge=0),
     limit: int = Query(default=100, ge=1, le=1000),
     db: Session = Depends(get_db),
-    current_user: dict = Depends(get_current_user),
 ):
     """List currently active locks with optional filters."""
     locks, total = coord_lock_service.get_active_locks(
@@ -39,7 +37,6 @@ def check_resource_locked(
     project_key: str = Query(...),
     resource: str = Query(...),
     db: Session = Depends(get_db),
-    current_user: dict = Depends(get_current_user),
 ):
     """Check whether a resource is currently locked."""
     lock = coord_lock_service.check_resource_locked(db, project_key, resource)
@@ -52,7 +49,6 @@ def check_resource_locked(
 def claim_lock(
     data: CoordSessionLockCreate,
     db: Session = Depends(get_db),
-    current_user: dict = Depends(get_current_user),
 ):
     """Claim a resource lock for a session."""
     lock = coord_lock_service.claim_lock(db, data)
@@ -63,7 +59,6 @@ def claim_lock(
 def release_all_session_locks(
     session_id: str = Query(..., description="Release all active locks held by this session"),
     db: Session = Depends(get_db),
-    current_user: dict = Depends(get_current_user),
 ):
     """Release all active locks for a session (call on session end)."""
     return coord_lock_service.release_all_session_locks(db, session_id)
@@ -74,7 +69,6 @@ def release_lock(
     lock_id: UUID,
     session_id: str = Query(..., description="Must match the session that claimed the lock"),
     db: Session = Depends(get_db),
-    current_user: dict = Depends(get_current_user),
 ):
     """Release a specific lock by ID."""
     lock = coord_lock_service.release_lock(db, lock_id, session_id)