feat: initial scaffold of agent_runner_api service Go :8486

migrations/003_worktrees.sql

@@ -0,0 +1,11 @@
+CREATE TABLE IF NOT EXISTS worktrees (
+    id          TEXT PRIMARY KEY,
+    run_id      TEXT NOT NULL,
+    path        TEXT NOT NULL,
+    branch      TEXT NOT NULL,
+    created_at  INTEGER NOT NULL,
+    removed_at  INTEGER,
+    FOREIGN KEY (run_id) REFERENCES runs(id) ON DELETE CASCADE
+);
+
+CREATE INDEX IF NOT EXISTS idx_worktrees_run ON worktrees(run_id);