feat: add SSH connection history with Ctrl+H navigation

Track SSH connections (configured + manual) with searchable history view.
Press Ctrl+H to view history, Ctrl+L to return. Add manual connections
to config with 'a'.

- Parse and store manual SSH connections
- History TUI with search and filtering
- Connection count and timestamps

feat(ui): add tabbed forms with height validation

- Implement General/Advanced tabs for add/edit forms
- Add terminal height detection with user-friendly warnings
- Add Ctrl+J/K tab navigation and SSH RemoteCommand/RequestTTY fields

feat(ui): add tabbed forms with height validation

- Implement General/Advanced tabs for add/edit forms
- Add terminal height detection with user-friendly warnings
- Add Ctrl+J/K tab navigation and SSH RemoteCommand/RequestTTY fields

feat: reorganize release notes

docs: update README.md and remove CONFIG.md

fix: remove discussion_category_name (discussions not enabled)

fix: make ValidateIdentityFile test robust for CI environments

- Remove assumption that ~/.ssh/id_rsa always exists
- Test tilde path expansion without asserting file existence

fix(ci): correct version injection in build workflow

- Change -X flag from cmd.version to cmd.AppVersion
- This fixes version display showing 'dev' instead of actual version
- Binaries will now display correct version when built via GitHub Actions

feat: add port forwarding history persistence

fix: resolve search behavior when cursor is not at top of list

- Fix search mode not triggering properly after navigation
- Preserve cursor position during filtering operations
- Add comprehensive UI tests for search functionality
- Improve search to include user field filtering