docs(audit): add M4 remaining-boundaries implementation plan (#23)

5 bundles: DB sync emissions, NotificationOutbox central, site Notify.Send,
Inbound API middleware, integration tests. M3-reality vocab baked in
(DbWrite/NotifyDeliver/NotifySend/InboundRequest/InboundAuthFailure).

docs/plans/2026-05-20-auditlog-m4-remaining-boundaries.md

@@ -0,0 +1,24 @@
+# Audit Log #23 — M4 Remaining Boundary Emission Implementation Plan
+
+> **For Claude:** REQUIRED SUB-SKILL: Use superpowers-extended-cc:subagent-driven-development (bundled cadence).
+
+**Goal:** Close every remaining script-trust-boundary emission gap: sync DB writes/reads via Database.Connection().Execute*/ExecuteReader, Notification Outbox central dispatcher attempts + terminal, site-side Notify.Send submission, and Inbound API middleware. Audit-write failure NEVER aborts the user-facing action across all five new code paths.
+
+**Vocabulary (M3 reality-locked):**
+- `AuditKind.DbWrite` (Channel=DbOutbound) for both Execute and ExecuteReader; `Extra` carries `{"op":"write"|"read","rowsAffected":N|"rowsReturned":N}`.
+- `AuditKind.NotifyDeliver` for each Notification Outbox attempt; `AuditStatus.Attempted` on attempts, `AuditStatus.Delivered|Failed|Parked|Discarded` on terminal.
+- `AuditKind.NotifySend` for site-emit at Notify.Send; `AuditStatus.Submitted`.
+- `AuditKind.InboundRequest` for happy-path inbound; `AuditStatus.Delivered`. `AuditKind.InboundAuthFailure` for 401; `AuditStatus.Failed`.
+- `AuditStatus.Failed` replaces "PermanentFailure" / "TransientFailure" terminal wording throughout.
+
+**Bundles:**
+- Bundle A — DB sync emissions (T1, T2)
+- Bundle B — NotificationOutbox central emissions (T3, T4, T5)
+- Bundle C — Site Notify.Send emission (T6)
+- Bundle D — Inbound API audit middleware (T7, T8)
+- Bundle E — Integration tests (T9, T10, T11, T12)
+- Final cross-bundle review + merge
+
+Each task follows the M2 Bundle F / M3 Bundle E emission pattern: capture timing, build AuditEvent with provenance, write via try/catch that swallows + logs, never propagate audit failure to the user-facing action. Mirror M2's ScriptRuntimeContext wrapper pattern where the emission is script-context-aware.
+
+Integration tests go in `tests/ScadaLink.AuditLog.Tests/Integration/` (component-level per M2 Bundle H + M3 Bundle G — the existing IntegrationTests factory disables Akka).