feat: add /search command powered by WarpGrep AI code search

[bhaktatejas922]

Summary

Adds a /search command that uses WarpGrep to perform AI-powered semantic code search. WarpGrep is an RL-trained search subagent that runs in an isolated context window, performing up to 8 parallel tool calls per turn across 4 turns, returning only relevant code spans.

Instead of writing regex patterns, describe what you're looking for in natural language:

/search Find where billing invoices are emailed to customers
/search How does the authentication middleware validate JWT tokens
/search Where is the database connection pool configured

How it works

1. User runs /search <query>
2. WarpGrep searches the codebase in its own context window (grep, read, list_dir)
3. Returns precise (file, start_line, end_line) spans with only the relevant code
4. Results are added to the chat context (following the /web pattern)
5. User is offered to add result files as editable

Changes

• aider/warpgrep.py (new) - WarpGrepClient implementing the multi-turn WarpGrep protocol with local ripgrep execution (Python grep fallback)
• aider/commands.py - Added cmd_search method (auto-registers as /search)
• aider/args.py - Added --warpgrep-api-key CLI argument
• tests/basic/test_warpgrep.py (new) - 21 unit tests covering XML parsing, repo structure generation, finish parsing, and mock HTTP

Configuration

Set one of:

• --warpgrep-api-key YOUR_KEY
• WARPGREP_API_KEY=...
• MORPH_API_KEY=...

Get a free API key at morphllm.com ($10/month free compute included).

Test plan

• 21 unit tests passing
• Manual test with a real repo and API key
• Verify /search appears in /help output

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}