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.

src/tool_schemas.py

@@ -369,7 +369,6 @@ FUNCTION_TOOL_SCHEMAS = [
                     "full": {"type": "boolean", "description": "Raise the download budget to the hard cap for large pages/files. Use only after a result reported partial content."},
                     "query": {"type": "string", "description": "Optional comma-separated terms used to select matching passages/pages from long documents or PDFs, for example 'DocVQA, ChartQA, TextVQA, Qwen2.5-VL-72B'."}
                 },
-                "anyOf": [{"required": ["url"]}, {"required": ["urls"]}],
                 "required": []
             }
         }