docs: add Docker build verification section (§17) — all 4 images pass, 1591 tests green

docs/devops/GITEA_NPM_REGISTRY_MIGRATION.md

@@ -642,3 +642,34 @@ After the initial migration was marked complete, a systematic audit was run acro
 ### Lesson learned
 
 Mobile workspace members (FlowMonk, NomGap, NoteLett) that were previously insulated from the `file:` → registry change because their lockfiles still resolved transitively will break when the lockfile is regenerated. Always run `GITEA_NPM_TOKEN=... pnpm install --no-frozen-lockfile` after converting mobile `package.json` refs.
+
+---
+
+## 17. Docker Build Verification (2026-03-24)
+
+After completing the migration and audit, all Dockerfiles were tested with actual `docker build` commands using the Gitea registry.
+
+### Bugs found and fixed during Docker verification
+
+| # | Finding | Severity | Fix | Repo |
+|---|---------|----------|-----|------|
+| 6 | MindLyst + LysnrAI Dockerfiles used shell syntax (`2>/dev/null \|\| true`) in COPY instructions | **BUG** | Removed — Docker COPY doesn't support shell redirects | both |
+| 7 | MindLyst web Dockerfile used `pnpm run build -- --webpack` — pnpm passes `--webpack` as directory arg | **BUG** | Changed to `npx next build --webpack` | `learning_multimodal_memory_agents` |
+| 8 | `@bytelyst/extraction` was missing from Gitea registry | **GAP** | Published (now 49 packages total) | common-plat |
+
+### Docker build results — all PASS
+
+| Repo | Image | Status |
+|------|-------|--------|
+| MindLyst | `mindlyst-backend:test` | ✅ |
+| MindLyst | `mindlyst-web:test` | ✅ |
+| LysnrAI | `lysnrai-backend:test` | ✅ |
+| LysnrAI | `lysnrai-dashboard:test` | ✅ |
+
+(Standard repos were already Docker-verified during the initial migration.)
+
+### Full verification sweep
+
+- **Backend tests**: 1,591 tests passing across all 10 repos
+- **Web typecheck**: 9/9 web apps typecheck clean
+- **Backend typecheck**: 10/10 repos typecheck clean