chore: add dev mode databases and data directories to gitignore

Added dev database files and dev_agent_data directory to gitignore
to prevent runtime dev data from being committed to the repository.

Patterns added:
- data/jobs_dev.db
- data/*_dev.db
- data/dev_agent_data/

This ensures dev mode runtime data remains local and doesn't pollute
version control.

.gitignore

@@ -66,6 +66,7 @@ configs/test_day_config.json
 # Data directories (optional - uncomment if needed)
 data/agent_data/test*/
 data/agent_data/*test*/
+data/dev_agent_data/
 data/merged_daily.jsonl
 data/merged_hour.jsonl
 
@@ -86,3 +87,5 @@ dmypy.json
 .worktrees/
 
 data/jobs.db
+data/jobs_dev.db
+data/*_dev.db