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/helpers/document_source.mjs

@@ -0,0 +1,32 @@
+// JS twin of tests/helpers/document_source.py: the document editor's whole
+// implementation set, so tests keep finding code as it moves out of the
+// static/js/document.js entry into static/js/document/.
+import { existsSync, readdirSync, readFileSync, statSync } from 'node:fs';
+import { dirname, join } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const HERE = dirname(fileURLToPath(import.meta.url));
+const JS = join(HERE, '..', '..', 'static', 'js');
+const ENTRY = join(JS, 'document.js');
+const IMPL_DIR = join(JS, 'document');
+
+function walk(dir) {
+  return readdirSync(dir).sort().flatMap(name => {
+    const path = join(dir, name);
+    if (statSync(path).isDirectory()) return walk(path);
+    return name.endsWith('.js') ? [path] : [];
+  });
+}
+
+/** Every file holding document-editor implementation, entry first. */
+export function documentSourcePaths() {
+  if (!existsSync(ENTRY)) {
+    throw new Error(`document editor entry point is missing: ${ENTRY}`);
+  }
+  return [ENTRY, ...(existsSync(IMPL_DIR) ? walk(IMPL_DIR).sort() : [])];
+}
+
+/** The whole implementation set as one string, entry first. */
+export function documentSource() {
+  return documentSourcePaths().map(path => readFileSync(path, 'utf8')).join('\n');
+}