chore: upgrade CodeQL to security-and-quality suite

Re-enable quality rules (unused-local-variable, trivial-conditional, etc.)
that were previously suppressed. The codebase is no longer raw decompiled
output, so quality alerts should reflect real issues now.

Also reopened all 47 previously dismissed quality alerts (#267-305, #338-341,
#347, #349, #351) so the next scan will re-evaluate them.

.github/workflows/codeql.yml

@@ -41,7 +41,7 @@ jobs:
         uses: github/codeql-action/init@v3
         with:
           languages: ${{ matrix.language }}
-          queries: security-extended
+          queries: security-and-quality
 
       - name: Autobuild
         uses: github/codeql-action/autobuild@v3