Add Issues module with aggregated cross-evaluation view (Vibe Kanban)

[cteyton]

Summary

Adds a new top-level Issues page (/issues) that aggregates all issues (errors and suggestions) across every completed evaluation into a single, paginated and filterable view. This provides a global overview of all findings in the database, making it easy to spot recurring patterns across repositories and evaluations.

Changes

Backend

• New API endpoint GET /api/issues with server-side pagination and filtering (evaluator, severity, repository, issue type, text search)
• Issue extractor utility (src/api/utils/issue-extractor.ts) — server-side extraction of issues from EvaluationOutput, handling both unified and independent evaluation formats
• Repository method getAllCompletedEvaluationsWithResults() on EvaluationRepository to load completed evaluations with their full result JSON
• Route registration in APIServer for the new /api/issues endpoint

Frontend

• IssuesPage component with filter sidebar (repository, evaluator, severity, issue type, text search) and paginated issue list
• useAggregatedIssues hook with debounced search, auto-fetch on filter/page changes, and filter state management
• Navigation integration — new "Issues" link with clipboard icon in the header, between "Latest" and "Evaluators"
• Routing — /issues route added to React Router
• Each issue displays its source context (repository name as link to evaluation, relative date, evaluator name) above the reused IssueCard component

Shared Types

• IAggregatedIssue and IAggregatedIssuesResponse types added to both backend (src/shared/types/api.ts) and frontend (frontend/src/types/evaluation.ts)

Implementation Details

• Issues are extracted from result_json blobs at query time (no schema migration needed). The server parses all completed evaluations, applies filters, then paginates.
• The issue extractor mirrors the frontend's parseAllIssues logic but runs server-side, handling both the object format ({perFileIssues, crossFileIssues}) and plain array format for evaluator results.
• IssueCard is reused with cloudMode={true} to hide feedback/bookmark buttons in the cross-evaluation context.
• Search is debounced at 300ms to avoid excessive API calls.

Tests

• 20 new tests across 2 test files:
  • issue-extractor.test.ts (8 tests) — unified/independent formats, cross-file issues, malformed JSON, skipped evaluators
  • issues.test.ts (12 tests) — pagination, all filter types, combined filters, empty DB, failed evaluation exclusion

Files Changed

File	Change
src/shared/types/api.ts	Added aggregated issue types
src/api/utils/issue-extractor.ts	New — Server-side issue extraction
src/api/utils/issue-extractor.test.ts	New — 8 tests
src/api/db/evaluation-repository.ts	Added getAllCompletedEvaluationsWithResults()
src/api/routes/issues.ts	New — IssuesRoutes with GET /api/issues
src/api/routes/issues.test.ts	New — 12 tests
src/api/index.ts	Route registration
frontend/src/types/evaluation.ts	Added aggregated issue types
frontend/src/hooks/useAggregatedIssues.ts	New — Data fetching hook
frontend/src/components/IssuesPage.tsx	New — Issues page component
frontend/src/App.tsx	Added /issues route
frontend/src/components/AppHeader.tsx	Added "Issues" nav link

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This PR was written using Vibe Kanban