* feat(#606): support auth mode + bearer token when adding HTTP MCP servers
- Extend AddMcpServerRequest with auth (none|header|oauth) and bearerToken
- Add auth mode FilterChip selector in HTTP add-server dialog
- Conditionally show masked bearer token field when auth == header
- Wire new fields through McpServersViewModel request builder
Backend contract: exactly one of url/command required; bearer_token
requires auth == "header"; args/env only for stdio. SnakeCase naming
strategy auto-serializes bearerToken -> bearer_token.
Fixes#606
* fix(#606): address agy review — remember PasswordVisualTransformation + FlowRow for auth chips
- Wrap PasswordVisualTransformation in remember {} to avoid per-recomposition allocation
- Use FlowRow for the 3 auth-mode FilterChips so they wrap on narrow screens instead of overflowing