config: move default sqlite_dir to .deer-flow/data

Keep SQLite databases alongside other DeerFlow-managed data
(threads, memory) under the .deer-flow/ directory instead of a
top-level ./data folder.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/packages/harness/deerflow/config/database_config.py

@@ -39,7 +39,7 @@ class DatabaseConfig(BaseModel):
         description=("Storage backend for both checkpointer and application data. 'memory' for development (no persistence across restarts), 'sqlite' for single-node deployment, 'postgres' for production multi-node deployment."),
     )
     sqlite_dir: str = Field(
-        default="./data",
+        default=".deer-flow/data",
         description=("Directory for SQLite database files. Checkpointer uses {sqlite_dir}/checkpoints.db, application data uses {sqlite_dir}/app.db."),
     )
     postgres_url: str = Field(

config.example.yaml

@@ -584,21 +584,23 @@ memory:
 #
 # Postgres mode: put your connection URL in .env as DATABASE_URL,
 # then reference it here with $DATABASE_URL.
-# Install the postgres driver: uv sync --extra postgres
+# Install the driver first:
+#   Local:  uv sync --extra postgres
+#   Docker: UV_EXTRAS=postgres docker compose build
 #
 # NOTE: When both `checkpointer` and `database` are configured,
 # `checkpointer` takes precedence for LangGraph state persistence.
 # If you use `database`, you can remove the `checkpointer` section.
 # database:
 #   backend: sqlite
-#   sqlite_dir: ./data
+#   sqlite_dir: .deer-flow/data
 #
 # database:
 #   backend: postgres
 #   postgres_url: $DATABASE_URL
 database:
   backend: sqlite
-  sqlite_dir: ./data
+  sqlite_dir: .deer-flow/data
 
 # ============================================================================
 # Run Events Configuration