Post React Compiler report as a sticky PR comment instead of a CI job

Review feedback: as a lint-matrix job it never fails and the report is
buried in the job summary. A dedicated workflow now runs the report on
every same-repo PR and posts it via sticky-pull-request-comment.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.github/workflows/lint.yml

@@ -29,7 +29,6 @@ jobs:
             'typecheck:ios',
             'typecheck:android',
             'typecheck:web',
-            'react-compiler:report',
           ]
     steps:
       - name: ⬇️ Check out Git repository