- Add _strip_masked_values() to skip masked placeholders in PUT endpoint,
preserving the original stored secret values instead of overwriting them
- Fix transport badge to gracefully handle unknown/future transport types
with a fallback that shows the raw string
- Add TestStripMaskedValues (5 tests) for the round-trip protection logic
- Addresses reviewer feedback on secret masking semantics and transport badge
- Add GET /api/mcp/servers (list with masked secrets)
- Add PUT /api/mcp/servers/<name> (add/update stdio and http servers)
- Add DELETE /api/mcp/servers/<name> (remove server)
- MCP section in System settings with server list, add/delete form
- Auto-detect transport type (stdio vs http) from server config
- Mask sensitive values (API keys, tokens, passwords) in list response
- Uses showConfirmDialog for delete confirmation (no native confirm)
- i18n: 21 keys across 7 locales
- 21 tests (list, save, delete, mask_secrets, validation)
