Is your feature request related to a problem? Please describe.
The CLI can list, save, load, and delete bookmarks, but it cannot search saved bookmarks by name or query text.

Describe the solution you would like
Add a whodb-cli bookmarks search [pattern] command that filters saved bookmarks by name or SQL text. It should follow the existing bookmarks output conventions and support table/plain/JSON-style formats consistently with the current bookmark commands.

Describe alternatives you have considered
Users can run bookmarks list and manually scan results, but that gets noisy once many bookmarks exist.

Additional context
Starting point:

• cli/cmd/bookmarks.go

Acceptance Criteria:

• whodb-cli bookmarks search [pattern] searches bookmark names and query text.
• Empty results behave like other bookmark commands.
• JSON output returns matching bookmark objects.
• Existing bookmark commands remain unchanged.
• Focused CLI tests cover name match, query match, no match, and JSON output.