docs: add repository context docs 🤖🤖🤖

[lirantal]

Adds standardized repository context for coding agents and maintainers:

• refreshes AGENTS.md with the shared routing template
• adds or links canonical docs for development, testing, architecture, and conventions
• adds RELEASE.md where missing for Changesets release guidance

No package behavior changes are included.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.57%. Comparing base (652403c) to head (15bf68e).

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #57   +/-   ##
=======================================
  Coverage   91.57%   91.57%           
=======================================
  Files          11       11           
  Lines        2029     2029           
  Branches      310      310           
=======================================
  Hits         1858     1858           
  Misses        160      160           
  Partials       11       11           

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