Document the PHPStan types fixture boundary

Clarify that phpstan.types.neon.dist owns only the committed types fixtures and must not be redirected at source or test files.

This prevents targeted analysis from overriding the configuration boundary and reporting irrelevant level-max errors for code outside the type-contract suite.

Author: binaryfire

AGENTS.md

@@ -700,6 +700,8 @@ The `tests/` directory is excluded from phpstan. Do not run phpstan on tests.
 
 Full PHPStan runs through `composer fix` at checkpoints. During implementation, use targeted PHPStan only when investigating or validating a specific type issue.
 
+`phpstan.types.neon.dist` validates only the committed `types/` fixtures. Never pass source or test paths to it.
+
 **When fixing phpstan errors:**
 
 1. **Investigate before coding.** For each error: read the code, check the Laravel equivalent's types (native and docblock), trace through callers and dependents. Report findings with the single, most correct fix.