feat(agent): telemetry + CI-gate quick wins from the "AI systems that ship" audit (#677)

* feat(agent): telemetry completeness + durability, CI gates, commit_method provenance

Quick wins from the "Building AI systems that ship" audit:

- mcp.tool_called gains errorMessage (message_sv, truncated 500 chars) on
  all failure exits; new mcp.skill_loaded event on every gnubok_load_skill
  (all tiers) so atom usage is finally measurable
- event_log: (event_type, created_at) index; cleanup cron keeps
  mcp.*/agent.* telemetry 180 days (delivery events stay 30)
- CI: lint ratchet (npm run check:lint — 60 legacy errors baselined,
  fails only on NEW errors) and a pg-real coverage gate (migrations
  touching trigger/RPC/RLS/DEFERRABLE require a *.pg.test.ts change;
  escape hatch: -- pg-test: covered-by/skip)
- journal_entries.commit_method CHECK widened with 'api_key'/'agent';
  the MCP approve path records 'api_key' truthfully instead of
  'user_accept' (agent_first_vision §8 P0-1). 'agent' is reserved — ALL
  MCP traffic (incl. claude.ai OAuth, whose access_token is a minted
  API key) authenticates as api_key today

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* feat(import): derive opening balances from prior-year #UB when SIE lacks #IB (#675)

SIE files exported without #IB 0 rows (only #UB -1) previously imported
with zero opening balances. getEffectiveOpeningBalances() now derives IB
from prior-year UB for balance-sheet accounts when explicit #IB is
absent, surfaces the derivation as an info issue in the import preview,
and excludes share-capital vouchers from opening-balance detection.
Detection regexes are shared between parser and importer so the two
checks cannot drift. 507 lib/import tests pass.

(Authored in a parallel session in this checkout; included per request.)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* fix(review): address PR #677 bot findings — RoPA entry, execFileSync, gate scope note

Triage of the compliance-swarm + Greptile findings:

Applied:
- .compliance/ropa.yaml: new mcp.telemetry processing activity declaring
  the 180-day mcp.*/agent.* retention, lawful basis, data categories, and
  the no-args/no-results minimisation (ISO A.8.10, GDPR Art.5(1)(c) —
  the retention split is now formally documented, referenced from the cron)
- check-pg-test-coverage.mjs: execFileSync with argv array — no shell, so
  a hostile base-ref can't inject (ASVS V13.2.1); verified an injection
  attempt exits 2 without executing
- check-pg-test-coverage.mjs: documented the PR-level (not per-migration)
  scope of the gate so reviewers know to check coverage per migration when
  a PR carries several risky migrations (Greptile P2)

Acknowledged, no change:
- errorMessage PII risk: messages are domain-mapped strings; event_log
  already persists far richer delivery payloads under the same RLS; now
  declared in ropa.yaml
- cron error envelope: errorResponse maps to the canonical safe envelope
  and the endpoint is CRON_SECRET-gated
- two-pass delete "partial state": TTL deletes are idempotent — the next
  daily run sweeps whatever a failed pass left behind
- skill_loaded actorLabel/sessionId: mirrors the pre-existing
  mcp.tool_called payload; sessionId is the join key the analytics exist for

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lib/pending-operations/commit.ts

@@ -104,14 +104,19 @@ export interface CommitOptions {
   userEmail?: string
   /**
    * commit_method recorded on any journal_entries created by this operation.
-   * Must match the CHECK constraint on journal_entries.commit_method:
-   * 'user_accept' | 'bulk_accept' | 'timing_ceiling' | 'migration' | 'legacy'.
-   * Single-approval route passes 'user_accept' (default); bulk-approval passes
-   * 'bulk_accept'. Defaults to 'user_accept' since the dispatcher is only
-   * invoked from human-approval paths after agent auto-commit was removed
-   * (migration 20260505190027_drop_agent_auto_commit).
+   * Must match the CHECK constraint on journal_entries.commit_method
+   * (migration 20260618120001): 'user_accept' | 'bulk_accept' |
+   * 'timing_ceiling' | 'migration' | 'legacy' | 'agent' | 'api_key'.
+   *
+   * Web-UI single-approval passes 'user_accept'; bulk-approval passes
+   * 'bulk_accept'. MCP approvals pass the relaying credential — 'api_key'
+   * (gnubok-mcp bridge) or 'agent' (OAuth connector) — so the immutable layer
+   * records that the acknowledgment was agent-relayed rather than a
+   * first-party human session (agent_first_vision.md §8 P0-1). Every path is
+   * still human-approval-gated; agent auto-commit was removed in
+   * 20260505190027_drop_agent_auto_commit.
    */
-  commitMethod?: 'user_accept' | 'bulk_accept'
+  commitMethod?: 'user_accept' | 'bulk_accept' | 'agent' | 'api_key'
 }
 
 // ── Helper: ensure fiscal period covers the date ──────────────────
@@ -2470,10 +2475,11 @@ async function commitCreateVoucher(
         notes: (params.notes as string) || undefined,
         lines,
       },
-      // commit_method records HOW it was committed, not who staged it. MCP-
-      // staged ops still go through human approval, so 'user_accept' (or
-      // 'bulk_accept' from the bulk route) is the correct value. The DB CHECK
-      // constraint rejects anything else (migration 20260420120001).
+      // commit_method records HOW it was committed, not who staged it.
+      // Web routes pass 'user_accept'/'bulk_accept'; the MCP approve path
+      // passes 'api_key'/'agent' so agent-relayed acknowledgments are
+      // distinguishable in the immutable layer. The DB CHECK constraint
+      // rejects anything else (migrations 20260420120001, 20260618120001).
       opts.commitMethod ?? 'user_accept'
     )