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/tools/editor_writing_smoke.py

@@ -14,8 +14,9 @@ from src.agent_tools import TOOL_HANDLERS
 import src.clean_agent_preview as runner
 from src.tool_policy import ToolPolicy
 from src.tool_schemas import FUNCTION_TOOL_SCHEMAS
+from tests.helpers.document_source import declaration
 from src.turn_contract import requested_capabilities, selected_tools_for_request, preserve_bound_editor_selected_tools, resolve_turn_contract
-menu=Path('static/js/document.js').read_text().split('const _AI_WRITING_ACTIONS = Object.freeze({',1)[1].split('});',1)[0]
+menu=declaration('_AI_WRITING_ACTIONS')
 actions=dict(re.findall(r"\s+(\w+): '([^']+)'",menu))
 image_body = '<p>Old caption</p><p><img src="/api/generated-image/fixture.png" alt="Fixture image" width="320" height="180"></p><p>Keep this paragraph unchanged.</p>'
 email_body = ('To: sam@example.com\nSubject: Re: Design review\nIn-Reply-To: <fixture@example.com>\n---\n'