#156 · SimpleX !get file retrieval + !files search parity

Context

Signal has !get <filename> (retrieve a specific archived file) and file search. SimpleX has !files/!download but no fetch-by-name.

Acceptance criteria

• [ ] !get <filename> returns a presigned download link for the named archived_files row.
• [ ] !files <query> searches archived_files and returns matches with links.
• [ ] Gated by isMinioConfigured().

Technical hints

• Signal reference: handleFileGet, handleFileSearch, handleFileGetFromSession in command-handler.ts.
• SimpleX target: new commands/utility/get.command.ts; extend files.command.ts. archived_files table exists (database/002_additional_tables.sql).

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