cleanup: remove unnecessary files and dependencies

- Remove duplicate database files (database.sqlite, database/jaryo.db)
- Remove test files (test-login.html)
- Remove redundant deployment scripts (deploy.sh, start-simple.bat)
- Remove vercel dev dependency and fix security vulnerabilities
- Clean up project structure for better maintainability

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

.claude/settings.local.json

@@ -71,7 +71,8 @@
       "WebSearch",
       "Bash(uvx:*)",
       "Bash(npm run:*)",
-      "Bash(tasklist:*)"
+      "Bash(tasklist:*)",
+      "Bash(npm audit:*)"
     ],
     "deny": [],
     "ask": [],