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/test_document_ai_preview_refresh_js.py

@@ -2,13 +2,13 @@
 
 import re
 from pathlib import Path
+from tests.helpers.document_source import document_source
 
 
-SRC = Path(__file__).resolve().parent.parent / "static/js/document.js"
 
 
 def _function_body(name: str) -> str:
-    text = SRC.read_text(encoding="utf-8")
+    text = document_source()
     match = re.search(rf"\n\s*(?:export\s+)?(?:async\s+)?function\s+{name}\([^)]*\)\s*\{{", text)
     assert match, f"{name} not found"