Add A0 GitHub issue context for knowledge gaps

[Svaag]

Summary

• Ingest GitHub issue bodies as sanitized excerpts and keep the raw body out of generated raw metadata.
• Mark GitHub Issue concepts as repo-owned canonical A0 context and emit source claims for repo, title, state, labels, and loop:knowledge-gap routing.
• Protect explicit GitHub issue references during context-pack retrieval so issue #327 survives tight budgets before broad repo context.
• Refresh OKF, JSONL exports, SQLite, reports, and eval baselines from current configured sources.

Validation

• uv run ruff check src tests
• uv run mypy --strict src
• uv run pytest
• uv run hyrule-knowledge validate okf
• uv run hyrule-knowledge quality --check
• uv run hyrule-knowledge export --check
• uv run hyrule-knowledge eval --check
• uv run hyrule-knowledge ledger --check
• uv run hyrule-knowledge ledger lifecycle --check
• uv run hyrule-knowledge scan-secrets okf exports reports evals ledger schema

Spot check

• Context pack for AS215932/network-operations issue #327 now includes generated/github/issues/network-operations/327 as the first A0 reference.