feat: add Pomodoro timer functionality with logging and project goals

- Implemented Pomodoro timer in the app, allowing users to start, pause, and stop sessions.
- Added context for managing Pomodoro state and actions.
- Integrated time logging for completed sessions to track productivity.
- Enhanced project settings to include time goals and Pomodoro settings.
- Created migration scripts to update the database schema for new project fields and time logs.
- Updated UI components to display Pomodoro controls and project time summaries.
- Added category filtering for projects in the project list view.

backend/migrate_add_time_logs.py

@@ -0,0 +1,34 @@
+"""
+Migration script to create the time_logs table.
+Run this once if you have an existing database.
+"""
+import sqlite3
+import os
+
+db_path = os.path.join(os.path.dirname(__file__), 'bit.db')
+
+if not os.path.exists(db_path):
+    print("No migration needed - new database will be created with the correct schema.")
+    exit(0)
+
+conn = sqlite3.connect(db_path)
+cursor = conn.cursor()
+
+try:
+    cursor.execute("""
+        CREATE TABLE IF NOT EXISTS time_logs (
+            id INTEGER PRIMARY KEY AUTOINCREMENT,
+            task_id INTEGER NOT NULL REFERENCES tasks(id) ON DELETE CASCADE,
+            minutes INTEGER NOT NULL,
+            note TEXT,
+            session_type TEXT DEFAULT 'manual',
+            logged_at DATETIME DEFAULT CURRENT_TIMESTAMP
+        )
+    """)
+    conn.commit()
+    print("Successfully created 'time_logs' table (or it already existed).")
+except Exception as e:
+    print(f"Error during migration: {e}")
+    conn.rollback()
+finally:
+    conn.close()