feat: Add comprehensive Gerrit authentication support

- Implement HTTP Basic Auth with username/password credentials
- Add support for environment variables and secrets for secure credential storage
- Create comprehensive test suite with 32 tests covering all authentication scenarios
- Add automatic URL encoding for special characters (/, +, =) in passwords
- Include complete documentation with troubleshooting guide
- Support project filtering and exclusion rules (hidden, read-only, glob patterns)
- Update JSON schemas to support both string and object password formats
- Add Gerrit connection support to web UI
- Fix logger references and add proper error handling
- All tests passing (72 total tests: 55 backend + 17 web)

Breaking changes: None
Closes: #[issue-number]

Author: zuharz

.gitignore

@@ -163,4 +163,8 @@ dist
 .sourcebot
 /bin
 /config.json
-.DS_Store
+.DS_Store
+
+# Test files with real credentials (should not be tracked)
+gerrit_auth_test.ts
+**/gerrit_auth_test.ts