Add network intercept/error monitor; document soak and Outline sync

- interceptNetworkCall + startNetworkErrorMonitor for page traffic
  (spy/mock + fail on silent 4xx/5xx), with unit tests
- docs/NETWORK.md, docs/IDEAS.md (OSS backlog), docs/OUTLINE.md
  (update Outline QA & Dev Playkit page on each release)
- Adoption pause: no other consumer repos until punimtag soak

docs/OUTLINE.md

@@ -0,0 +1,34 @@
+# Outline live docs checklist
+
+Canonical prose stays in git (`README.md`, `docs/*`, `ROADMAP.md`).
+Browsable front door: **Outline** → collection **QA & Dev** → doc **Playkit**
+(`https://notes.levkin.ca`).
+
+## When to update Outline
+
+Update the Outline Playkit page **whenever playkit ships a release** (after the
+tag / Gitea release is green), or whenever you merge a docs-only change that
+changes consumer behavior:
+
+1. Tag / release finished (or main docs PR merged)
+2. Open Outline → QA & Dev → Playkit
+3. Sync at least: current version pin, “what’s in the box”, install snippet,
+   link to CHANGELOG / ROADMAP / NETWORK.md
+4. Optional: `make outline-setup` from ansible only if you maintain seed notes there —
+   prefer editing the living page by hand so it stays readable
+
+Paste template (adjust version):
+
+```markdown
+# @levkin/playkit
+
+Shared Playwright + API e2e kit. **Source of truth is the git repo.**
+
+- Repo: https://git.levkin.ca/ilia/playkit
+- Current: vX.Y.Z
+- Consumers: punimtag (e2e/) — *pause further adoption until soak completes*
+
+## Quick links
+- README · CONSUMER.md · NETWORK.md · IDEAS.md · ROADMAP · CHANGELOG
+- Metrics: dash.levkin.ca → Live — Playkit e2e
+```