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.

tests/editor-layer-styles.mjs

@@ -1,6 +1,7 @@
 import assert from 'node:assert/strict';
 import { readFile } from 'node:fs/promises';
 import { chromium } from 'playwright';
+import { appCss } from './helpers/stylesheets.mjs';
 
 const browser = await chromium.launch({ headless: true });
 try {
@@ -46,7 +47,7 @@ try {
     return result;
   });
   assert.equal(results.length, 7);
-  await page.addStyleTag({ content: await readFile(new URL('../static/style.css', import.meta.url), 'utf8') });
+  await page.addStyleTag({ content: await appCss() });
   await page.evaluate(async () => {
     const { openLayerStyleMenu } = await import('/layer-style-menu.js');
     document.querySelector('#fx').onclick = event => { event.stopPropagation(); openLayerStyleMenu(event.currentTarget, () => {}); };