Add D1 migration baseline

cloudflare/migrations/0002_sync.sql

@@ -0,0 +1,62 @@
+CREATE TABLE IF NOT EXISTS sync_objects (
+  user_id TEXT NOT NULL,
+  object_id TEXT NOT NULL,
+  object_type TEXT NOT NULL,
+  payload_inline BLOB,
+  payload_r2_key TEXT,
+  payload_hash TEXT NOT NULL,
+  schema_rev INTEGER NOT NULL,
+  logical_clock INTEGER NOT NULL,
+  device_id TEXT NOT NULL,
+  created_at INTEGER NOT NULL,
+  updated_at INTEGER NOT NULL,
+  deleted_at INTEGER,
+  PRIMARY KEY (user_id, object_id),
+  CHECK (payload_inline IS NULL OR payload_r2_key IS NULL),
+  CHECK (deleted_at IS NOT NULL OR payload_inline IS NOT NULL OR payload_r2_key IS NOT NULL)
+);
+
+CREATE INDEX IF NOT EXISTS idx_sync_objects_delta
+  ON sync_objects (user_id, object_type, logical_clock, updated_at);
+
+CREATE TABLE IF NOT EXISTS sync_change_log (
+  change_id INTEGER PRIMARY KEY AUTOINCREMENT,
+  user_id TEXT NOT NULL,
+  object_id TEXT NOT NULL,
+  object_type TEXT NOT NULL,
+  operation TEXT NOT NULL CHECK (operation IN ('upsert', 'delete')),
+  payload_hash TEXT NOT NULL,
+  logical_clock INTEGER NOT NULL,
+  device_id TEXT NOT NULL,
+  created_at INTEGER NOT NULL,
+  UNIQUE (user_id, object_id, logical_clock, device_id, operation)
+);
+
+CREATE INDEX IF NOT EXISTS idx_sync_change_log_pull
+  ON sync_change_log (user_id, change_id);
+
+CREATE TABLE IF NOT EXISTS sync_snapshots (
+  user_id TEXT NOT NULL,
+  snapshot_id TEXT NOT NULL,
+  r2_key TEXT NOT NULL,
+  payload_hash TEXT NOT NULL,
+  schema_rev INTEGER NOT NULL,
+  logical_clock INTEGER NOT NULL,
+  device_id TEXT NOT NULL,
+  size_bytes INTEGER NOT NULL CHECK (size_bytes > 0),
+  created_at INTEGER NOT NULL,
+  PRIMARY KEY (user_id, snapshot_id)
+);
+
+CREATE INDEX IF NOT EXISTS idx_sync_snapshots_latest
+  ON sync_snapshots (user_id, created_at);
+
+CREATE TABLE IF NOT EXISTS sync_tombstones (
+  user_id TEXT NOT NULL,
+  object_id TEXT NOT NULL,
+  object_type TEXT NOT NULL,
+  logical_clock INTEGER NOT NULL,
+  device_id TEXT NOT NULL,
+  deleted_at INTEGER NOT NULL,
+  PRIMARY KEY (user_id, object_id)
+);