chore: Remove temporary discovery output files and add tmp/ to gitignore

Remove temporary files generated during two-phase discovery:
- global_database_summary.md (17KB discovery report)
- question_templates.md (38KB question templates)

Add scripts/mcp/DiscoveryAgent/ClaudeCode_Headless/tmp/ to .gitignore
to prevent tracking of temporary discovery outputs in the future.

.gitignore

@@ -179,3 +179,4 @@ GEMINI.md
 # Database discovery output files
 discovery_*.md
 database_discovery_report.md
+scripts/mcp/DiscoveryAgent/ClaudeCode_Headless/tmp/