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_editor_writing_action_routing.py

@@ -1,6 +1,5 @@
 """Writing-menu source text must not redirect the requested editor operation."""
 import re
-from pathlib import Path
 from types import SimpleNamespace
 
 import pytest
@@ -15,8 +14,9 @@ from src.turn_contract import (
 )
 from src.tool_schemas import FUNCTION_TOOL_SCHEMAS
 from src.tool_policy import ToolPolicy
+from tests.helpers.document_source import declaration
 
-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))