refactor: tighten exception handling in database.py and add BLE lint rule

- Wrap duckdb.connect() in try/except with specific duckdb.Error
- Replace bare  with  in _init_database
- Replace broad  with  for ALTER TABLE
- Add ruff BLE (blind except) lint rule to prevent regressions
- Add tests verifying graceful error handling for connect, insert, query

P2-002: Fix broad exception handling

tests/test_database_exceptions.py

@@ -0,0 +1,38 @@
+import logging
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+from database import MotionDatabase
+
+
+class TestMotionDatabaseExceptionHandling:
+    @patch("database.duckdb")
+    def test_init_database_catches_duckdb_connect_errors(self, mock_duckdb, tmp_path):
+        mock_duckdb.Error = Exception
+        mock_duckdb.connect.side_effect = mock_duckdb.Error("db locked")
+        db = MotionDatabase(db_path=str(tmp_path / "test.db"))
+        assert db._file_mode is True
+
+    @patch("database.duckdb")
+    def test_insert_motion_catches_errors_and_returns_false(self, mock_duckdb, tmp_path):
+        mock_duckdb.Error = Exception
+        mock_conn = MagicMock()
+        mock_duckdb.connect.return_value = mock_conn
+
+        db = MotionDatabase(db_path=str(tmp_path / "test.db"))
+        # Now make insert_motion fail
+        mock_conn.execute.side_effect = mock_duckdb.Error("constraint violation")
+        result = db.insert_motion({"title": "Test", "date": "2024-01-01", "url": "http://test"})
+        assert result is False
+
+    @patch("database.duckdb")
+    def test_query_motions_catches_errors_and_returns_empty_list(self, mock_duckdb, tmp_path):
+        mock_duckdb.Error = Exception
+        mock_conn = MagicMock()
+        mock_duckdb.connect.return_value = mock_conn
+
+        db = MotionDatabase(db_path=str(tmp_path / "test.db"))
+        mock_conn.execute.side_effect = mock_duckdb.Error("syntax error")
+        result = db.get_filtered_motions()
+        assert result == []