chore: make codecov checks informational (#456)

## Summary
- Codecov status checks will no longer block PR merges
- Coverage reports will still be generated and visible, but won't fail
the build

🤖 Generated with [Claude Code](https://claude.com/claude-code)

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> Configures Codecov to report coverage without blocking merges.
> 
> - Adds `codecov.yml` setting
`coverage.status.project.default.informational` and
`coverage.status.patch.default.informational` to `true`
> - Makes Codecov status checks informational while keeping reports
generated and visible
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
9416ee2. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Co-authored-by: Claude Opus 4.5 <[email protected]>

Author: jdx

codecov.yml

@@ -0,0 +1,8 @@
+coverage:
+  status:
+    project:
+      default:
+        informational: true
+    patch:
+      default:
+        informational: true