feat: agent coordination system (workflows, locks, components, messages)

Adds /api/coord/* endpoints for real-time cross-session coordination:
- coord_workflows: named units of work per project
- coord_work_items: tasks within workflows with dependency chains
- coord_session_locks: exclusive resource locks with auto-expiry (TTL)
- coord_component_states: live component state per project (upsert)
- coord_messages: cross-session messaging and broadcasts
- /api/coord/status: cross-project snapshot endpoint

Replaces PROJECT_STATE.md as the coordination layer for Claude sessions.

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

api/services/coord_component_service.py

@@ -0,0 +1,63 @@
+"""Service layer for CoordComponentState."""
+
+from typing import Optional
+
+from fastapi import HTTPException, status
+from sqlalchemy.dialects.mysql import insert
+from sqlalchemy.orm import Session
+
+from api.models.coord_component_state import CoordComponentState
+from api.schemas.coord_component_state import CoordComponentStateUpsert
+
+
+def get_component_states(
+    db: Session,
+    project_key: Optional[str] = None,
+) -> list[CoordComponentState]:
+    """Return all component states, optionally filtered by project."""
+    q = db.query(CoordComponentState)
+    if project_key:
+        q = q.filter(CoordComponentState.project_key == project_key)
+    return q.order_by(CoordComponentState.project_key, CoordComponentState.component).all()
+
+
+def upsert_component_state(
+    db: Session,
+    project_key: str,
+    component: str,
+    data: CoordComponentStateUpsert,
+) -> CoordComponentState:
+    """Insert or update a component state using MariaDB ON DUPLICATE KEY UPDATE."""
+    try:
+        stmt = insert(CoordComponentState).values(
+            project_key=project_key,
+            component=component,
+            state=data.state,
+            version=data.version,
+            notes=data.notes,
+            updated_by=data.updated_by,
+        )
+        stmt = stmt.on_duplicate_key_update(
+            state=stmt.inserted.state,
+            version=stmt.inserted.version,
+            notes=stmt.inserted.notes,
+            updated_by=stmt.inserted.updated_by,
+        )
+        db.execute(stmt)
+        db.commit()
+
+        record = (
+            db.query(CoordComponentState)
+            .filter(
+                CoordComponentState.project_key == project_key,
+                CoordComponentState.component == component,
+            )
+            .first()
+        )
+        return record
+    except Exception as e:
+        db.rollback()
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail=f"Failed to upsert component state: {e}"
+        )