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.

static/index.html

@@ -246,8 +246,32 @@
        real request is discarded and the font fetched a second time. -->
   <link rel="preload" as="font" type="font/woff2" crossorigin href="/static/fonts/FiraCode-Regular.woff2">
   <link rel="preload" as="font" type="font/woff2" crossorigin href="/static/fonts/FiraCode-SemiBold.woff2">
-  <link rel="stylesheet" href="/static/style.css?v=20260921chatgptusage2">
-  <link rel="modulepreload" href="/static/app.js?v=20260921chatgptusage2">
+  <link rel="stylesheet" href="/static/css/00-tokens.css?v=20260929csssplit">
+  <link rel="stylesheet" href="/static/css/01-agent-chat.css?v=20260929csssplit">
+  <link rel="stylesheet" href="/static/css/02-compare.css?v=20260929csssplit">
+  <link rel="stylesheet" href="/static/css/03-agent-chat.css?v=20260929csssplit">
+  <link rel="stylesheet" href="/static/css/04-memory.css?v=20260929csssplit">
+  <link rel="stylesheet" href="/static/css/05-documents.css?v=20260929csssplit">
+  <link rel="stylesheet" href="/static/css/06-admin-settings.css?v=20260929csssplit">
+  <link rel="stylesheet" href="/static/css/07-documents.css?v=20260929csssplit">
+  <link rel="stylesheet" href="/static/css/08-skills.css?v=20260929csssplit">
+  <link rel="stylesheet" href="/static/css/09-gallery.css?v=20260929csssplit">
+  <link rel="stylesheet" href="/static/css/10-cookbook.css?v=20260929csssplit">
+  <link rel="stylesheet" href="/static/css/11-tasks.css?v=20260929csssplit">
+  <link rel="stylesheet" href="/static/css/12-gallery.css?v=20260929csssplit">
+  <link rel="stylesheet" href="/static/css/13-image-editor.css?v=20260929csssplit">
+  <link rel="stylesheet" href="/static/css/14-email.css?v=20260929csssplit">
+  <link rel="stylesheet" href="/static/css/15-notes.css?v=20260929csssplit">
+  <link rel="stylesheet" href="/static/css/16-calendar.css?v=20260929csssplit">
+  <link rel="stylesheet" href="/static/css/17-research.css?v=20260929csssplit">
+  <!-- Panel stylesheets split out of style.css for maintainability. They are
+       eager and their order is load-bearing: the cascade is the concatenation of
+       these files in this order, so they must stay in this order here and in the
+       PRECACHE list in sw.js. None of them is lazy-loaded. -->
+  <link rel="stylesheet" href="/static/css/documents-gallery-editor.css?v=20260929csssplit">
+  <link rel="stylesheet" href="/static/css/email-calendar-notes-tasks.css?v=20260929csssplit">
+  <link rel="stylesheet" href="/static/css/cookbook-research-memory-settings.css?v=20260929csssplit">
+  <link rel="modulepreload" href="/static/app.js?v=20260929csssplit">
 <link rel="modulepreload" href="/static/js/chat.js?v=20260917toolttft1">
   <link rel="modulepreload" href="/static/js/ui.js?v=20260916largetoolscroll1">
   <link rel="modulepreload" href="/static/js/sessions.js">
@@ -1527,6 +1551,15 @@
             <span>System</span>
           </button>
           </div>
+
+          <!-- Build provenance, pinned below the scrolling nav so it stays at
+               the bottom-left of the panel: the version this build registers
+               and the commit the running process actually loaded. Populated
+               from /api/version; stays hidden until that answers. -->
+          <div class="settings-sidebar-build admin-only" id="settings-sidebar-build" hidden>
+            <span class="settings-sidebar-build-version" id="settings-sidebar-build-version"></span>
+            <span class="settings-sidebar-build-commit" id="settings-sidebar-build-commit"></span>
+          </div>
         </div>
         <div class="settings-panels">
 
@@ -2634,7 +2667,7 @@
 <script type="module" src="/static/js/censor.js"></script>
 <script type="module" src="/static/js/settings.js?v=20260912writingstyle3"></script>
 <script type="module" src="/static/js/assistant.js?v=20260912firefoxjscleanup1"></script>
-<script type="module" src="/static/app.js?v=20260921chatgptusage2"></script>  <!-- app.js must be LAST -->
+<script type="module" src="/static/app.js?v=20260929csssplit"></script>  <!-- app.js must be LAST -->
   <script type="module" src="/static/js/init.js?v=20260829chatstyle12"></script>
 <script type="module" src="/static/js/a11y.js"></script>
 <script nonce="{{CSP_NONCE}}">if('serviceWorker' in navigator){navigator.serviceWorker.register('/static/sw.js?v=20260916autoscroll1').catch(()=>{});}</script>