Add Wiki knowledge retrieval

[dkstm95]

What changed

• Add deterministic retrieval for active Wiki knowledge pages.
• Rank matches by title, slug, summary, headings, body text, page kind, and path.
• Normalize common English question words and a narrow set of Korean suffixes.
• Bind selected pages and their declared raw sources into provider-neutral answer tasks.
• Keep factual knowledge context separate from behavioral memory guidance.
• Add CLI, agent-runtime, and local-tool entry points.
• Document the retrieval contract, limitations, and evidence rules.

Why

The previous query path selected pages with a broad token match and filesystem-order truncation. It
did not expose a validated retrieval artifact or consistently bind the raw sources behind a selected
page. This made relevance hard to inspect and allowed different entry points to carry different
evidence.

This change gives every query path the same deterministic selection and evidence boundary. Compiled
Wiki pages guide navigation and synthesis. Only their bound raw sources support factual accepted
claims.

Impact

wiki answer task can now retrieve useful Wiki context without requiring --sources. Callers may
still supply --sources to add trusted evidence. Prepared contexts and answer tasks become stale
when selected pages, ranking inputs, or evidence change.

The implementation remains model-provider neutral and works with the existing subscription runner.

Validation

• pnpm check
• 261 tests passed
• line coverage: 95.89%
• branch coverage: 90.51%
• build, distribution smoke test, and documentation checks passed