feat: add bookkeeper skill

[ArgonautWorks]

What changed

• add a deterministic public bookkeeper skill with typed transaction, chart-of-accounts, and prior-period inputs
• categorize only when a transaction binds uniquely to an existing chart account
• return confidence, reason, anomaly findings, and exact matched/unmatched reconciliation totals
• seal ambiguous, unknown-account, and out-of-period batches as needs_review without guessing
• expose explicit no-write evidence: no ledger mutation, writes, external effects, network access, or downstream dispatch

Why

Bookkeeping reconciliation should be explainable without implying that a journal was posted. This package turns admitted transaction lines into a bounded read-only artifact and makes unmatched or anomalous evidence visible rather than weakening the account-binding rule.

Validation

• runx-cli 0.8.2
• node --check skills/bookkeeper/run.mjs — passed
• runx skill inspect ./skills/bookkeeper --json — ready, fully bound, no unresolved edges
• runx harness ./skills/bookkeeper -R <fresh-dir> --json — 8/8 cases passed, zero assertion errors
• hosted registry publish gate — passed; argonautworks/bookkeeper@0.1.0 published
• digest-pinned clean install — passed; installed package inspected ready
• post-publish registry dogfood — sealed; 3 categorized, 0 anomalies, matched 3, unmatched 0
• production receipt verification — valid digest, content address, and Ed25519 signature; zero findings
• git diff --check — passed

Public evidence

• Registry: https://runx.ai/x/argonautworks/bookkeeper@0.1.0
• Exact source: https://github.com/ArgonautWorks/runx/tree/00988964a8731fb30e530b9584629ffcdc6edd28/skills/bookkeeper
• Evidence packet: https://github.com/ArgonautWorks/frantic-89-bookkeeper-evidence/tree/a55c5d80077463800ec240dc6a9cd4c9ecade1ee
• Machine evidence: https://raw.githubusercontent.com/ArgonautWorks/frantic-89-bookkeeper-evidence/a55c5d80077463800ec240dc6a9cd4c9ecade1ee/evidence.json
• Verification results: https://raw.githubusercontent.com/ArgonautWorks/frantic-89-bookkeeper-evidence/a55c5d80077463800ec240dc6a9cd4c9ecade1ee/verification.json
• Delivery report: https://raw.githubusercontent.com/ArgonautWorks/frantic-89-bookkeeper-evidence/a55c5d80077463800ec240dc6a9cd4c9ecade1ee/report.md
• Dogfood receipt: runx:receipt:sha256:c2c3ea70e5a4e208f7e4d4e86d2386ea44182cb95f5d5e57fd48619ab3d9b130

Frantic bounty: https://gofrantic.com/bounties/89