chore: add code summary

[ThirdEyeSqueegee]

Issue #, if available:
N/A

Description of changes:
Generated with claude-opus-4.6-1m

Kiro CLI has a new code intelligence feature which uses Tree-sitter and LSP to create a code summary for a project. Ran /code summary on main. AGENTS.md should automatically be picked up by AI agents when invoked in the project's root dir. .agents/summary/index.md must be manually added to the agent's context (this should be a one-time local config change). To keep the summary up to date, future PRs should adopt the following workflow:

1. Finish revising the PR
2. Check out feature branch locally
3. Install the Rust language server as described in Kiro CLI docs
4. Invoke Kiro CLI
5. Run /code init
6. Run /code summary
7. In the list of options, keep all defaults except for update mode: set this to true
8. The .last_commit file will be used to incrementally update the code summary
9. Commit the generated changes to the code summary to feature branch

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.14%. Comparing base (e425e69) to head (4ca7c46).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #169   +/-   ##
=======================================
  Coverage   92.14%   92.14%           
=======================================
  Files          14       14           
  Lines        2405     2405           
  Branches     2405     2405           
=======================================
  Hits         2216     2216           
  Misses        143      143           
  Partials       46       46           

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