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/documentSelectionCaret.mjs

@@ -1,8 +1,8 @@
-import { readFileSync } from 'node:fs';
 import assert from 'node:assert/strict';
+import { documentSource } from './helpers/document_source.mjs';
 import { chromium } from 'playwright';
 
-const source = readFileSync('static/js/document.js', 'utf8');
+const source = documentSource();
 const start = source.indexOf('  function clearSelection(');
 const cleanup = source.slice(start, source.indexOf('  function clearSelectionAt(', start));
 assert.equal((source.match(/if \(_selections.length\) clearSelection\(\{ preserveCaret: true \}\);/g) || []).length, 2);