merge: reconcile PR 40 with current lab

Integrate lab fff55a78 into PR #40 (cc25d5ba). Lab's modular email
backend/frontend, modular settings, split stylesheets (static/style.css
stays deleted), procfs compatibility, and request-scoped TurnContract
authority win; PR #40's routing classifiers, editor/email/task features,
and style.css changes are ported into lab's module and stylesheet homes.

Integration fixes:
- settings/api.js imports ui.js under its canonical versioned URL
- browser observations keep legacy CAPTCHA/access-block evidence
- artifact turns do not re-trigger broad-web research recovery
- env reference documents PR test-tool variables; page regenerated

PR #40 defects surfaced by lab gates and fixed here:
- web_fetch generic schema drops top-level anyOf (OpenAI contract);
  the compact preview contract still requires url or urls
- get_weather registered as a brokered network read
- new lazy editor modules precached for offline use
- SearXNG pin mirrored into GPU standalone compose files
- image model picker again skips offline endpoints

Tests updated where PR #40 changed behaviour on purpose, and PR tests
moved onto lab's document_source helpers.

ACKNOWLEDGMENTS.md

@@ -47,7 +47,7 @@ just composed.
 
 | Service | Image | Purpose | License |
 |---|---|---|---|
-| [SearXNG](https://github.com/searxng/searxng) | `searxng/searxng:2026.5.31-7159b8aed` (pinned tag; see compose) | Default metasearch backend | AGPL-3.0 |
+| [SearXNG](https://github.com/searxng/searxng) | `searxng/searxng:2026.9.25-12f8b6515` (pinned tag; see compose) | Default metasearch backend | AGPL-3.0 |
 | [ChromaDB](https://github.com/chroma-core/chroma) | `chromadb/chroma:latest` | Vector store for memory / RAG | Apache-2.0 |
 | [ntfy](https://github.com/binwiederhier/ntfy) | `binwiederhier/ntfy` | Push notifications (self-hosted reminders) | Apache-2.0 / GPL-2.0 |