[Improvement] Increase test coverage from ~25% to meaningful thresholds

[d-oit]

Description

Current test coverage is extremely low, far below the 80% target mentioned in agents-docs/CONFIG.md:

Metric	Current	Target
Branches	14%	80%
Functions	16%	80%
Lines	25%	80%
Statements	24%	80%

Untested Components (0% coverage)

• Chat.tsx — No unit tests
• AIHarness.tsx — No unit tests
• ExportPanel.tsx — No unit tests
• MindMapView.tsx — No unit tests
• GraphView.tsx — No unit tests
• ErrorBoundary.tsx — No unit tests
• ThemeSwitcher.tsx — No unit tests
• MobileDrawer.tsx — No unit tests
• DbProvider.tsx — No unit tests
• openrouter.ts / kilo.ts — No unit tests (LLM providers)
• CLI (cli/index.ts, cli/db.ts) — Zero test coverage

Partially Tested

• search.ts — Semantic search/embeddings not tested
• nlp.ts — Only basic tests, no edge cases
• resolver.ts — Limited error path testing

Recommended Approach

1. Phase 1 (Target: 50%): Add tests for all untested components with critical paths
2. Phase 2 (Target: 65%): Add edge case tests and error path coverage
3. Phase 3 (Target: 80%): Add comprehensive integration tests

Priority Test Targets

1. ExportPanel (security-critical — XSS)
2. AIHarness (complex async logic)
3. Chat (user-facing feature)
4. CLI commands
5. LLM providers (mock API calls)

Acceptance Criteria

• Coverage thresholds raised to at least 50% initially
• All untested components have at least basic tests
• CLI has integration tests
• Security-critical paths (export, LLM) have dedicated tests
• CI runs test:coverage and reports results