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/historyResumeRendering.test.mjs

@@ -57,6 +57,7 @@ async function setup() {
     window.startsContinuationRound = (await import('/static/js/turnRendering.js')).startsContinuationRound;
     window.applyModelRouteEventState = (await import('/static/js/chatModelProvenance.js')).applyModelRouteEventState;
     window.createTerminalStreamError = (await import('/static/js/chatStreamErrors.js')).createTerminalStreamError;
+    window.generatedImageResult = (await import('/static/js/generatedImageResult.js')).generatedImageResult;
     window.addMessage = (0, eval)('(' + addMessage + ')');
     window.resumeStream = (0, eval)('(' + resume + ')');
     window.chatRenderer = { addMessage: window.addMessage, recordSessionMetricsCost: noop, buildSourcesBox, buildFindingsBox, buildRagSourcesBox };