chore(frontend): remove unused variables in CodebaseAnalytics.vue (#2405)

[mrveiss]

Summary

• Remove 18 unused destructured variables from composable calls in CodebaseAnalytics.vue
• Variables were left behind after panel refactoring (Refactor: decompose CodebaseAnalytics.vue (11,668 lines) #1469, Cleanup: wire useCodebaseDataLoaders composable or remove dead code (#1469 follow-up) #2228, Refactor: decompose CodebaseAnalytics.vue script section (3200+ lines, 503 functions) #2230)
• Eliminates ESLint @typescript-eslint/no-unused-vars warnings

Closes #2405

Test plan

• Removed variables confirmed unused in template and script
• No runtime behavior changes — cosmetic cleanup only

[github-actions]

✅ SSOT Configuration Compliance: Passing

🎉 No hardcoded values detected that have SSOT config equivalents!