Globs in AGENTS.md

Your AGENTS.md files can now include other context files dynamically, with glob mentions and filters, so you can give more granular guidance to the agent.

For example, to apply language-specific coding rules:

1. Put See @docs/*.md anywhere in your AGENTS.md file.

2. Create a file docs/typescript-conventions.md with:

   ---
   globs:
     - '**/*.ts'
   ---
   
   Follow these TypeScript conventions:
   
   - Never use the `any` type
   - ...
   

3. Repeat for other languages.

There's nothing special about @docs/*.md; you could instead mention @.agent/rules/*.md or @.cursor/rules/*.mdc or anywhere else you want these rules to live.

These @-mentioned files with globs will only be included if Amp has read a file matching any of the globs (in the example above, any TypeScript file). Use /agent-files (CLI) or hover over X% of 968k (editor extension) to see the guidance files in use.