Cleanup: wire useCodebaseDataLoaders composable or remove dead code (#1469 follow-up)

[mrveiss]

Problem

During the decomposition of CodebaseAnalytics.vue in PR #2225 (#1469), the composable autobot-frontend/src/composables/analytics/useCodebaseDataLoaders.ts (656 lines) was created but never imported or used by any component. It contains reusable data-loading functions (call graph, charts, unified report, environment, Redis health, cross-language, cached loaders) that should replace inline fetch logic in the parent.

Discovered During

Implementation of #1469 (PR #2225)

Expected Outcome

Either:

1. Wire useCodebaseDataLoaders into CodebaseAnalytics.vue, replacing the ~500 inline data-loading functions in the script section, OR
2. Remove it if the approach is wrong

Impact

Medium — 656 lines of unreachable code; the parent script section remains bloated at 3200+ lines because the composable wasn't integrated.

[mrveiss]

Closed via PR #2253 merge to Dev_new_gui.