audit: 2026-05-30 full-codebase audit — report, issues, docs, runbooks

Full-codebase-audit 2026-05-30 outputs:
- Audit report: 09 - Audits/Full Codebase Audit - 2026-05-30.md
- 81 issue files ISSUE-055..135 (decisions + 1 skipped no-brainer).
- Scanner docs from scratch (was zero): architecture, data model, API ref, payment
  flow, operations runbook + repo README.
- Doc-sync updates across API reference, data models, flows, design system.
- Secret Rotation Runbook (08 - Operations) for the exposed credentials.
- Reusable workflow guide (07 - Development) + .claude/workflows/full-codebase-audit.js.

Issues remain status:open intentionally — the code fixes are uncommitted-then-committed
working-tree changes per repo and aren't "resolved" until merged/deployed.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Issues/ISSUE-091-frontend-dual-socket-connections-socketprovider-and-socketserv.md

@@ -0,0 +1,39 @@
+---
+issue: 091
+title: "Frontend: dual socket connections (SocketProvider + socketService singleton)"
+severity: medium
+domain: Realtime
+labels: [bug, frontend, performance]
+status: open
+created: 2026-05-30
+source: Full Codebase Audit 2026-05-30
+---
+
+# Frontend: dual socket connections (SocketProvider + socketService singleton)
+
+**Severity:** medium
+**Domain:** Realtime
+**Labels:** bug, frontend, performance
+
+## Description
+
+`src/socket/lib/socket-service.ts:217` creates a standalone socket.io connection separate from the `SocketProvider` context. Both may connect simultaneously, resulting in duplicate connections to the backend, doubled event delivery, and doubled auth overhead.
+
+## Options
+
+1. Make `socketService` delegate to the `SocketProvider` connection (single source of truth).
+2. Migrate all `actions/chat.ts` usages to the context provider and delete `socketService`.
+3. Keep both but ensure only one actually connects.
+
+## Recommendation
+
+Consolidate onto `SocketProvider` and refactor `socketService` callers; remove the duplicate connection. This is a large refactor.
+
+## Affected Files
+
+- `frontend/src/socket/lib/socket-service.ts:217`
+- `frontend/src/actions/chat.ts` — socketService callers
+
+## References
+
+- [Full Codebase Audit 2026-05-30](../09%20-%20Audits/Full%20Codebase%20Audit%20-%202026-05-30.md) — DEC-21