New web UI with iPhone web app

Redesigned status, log, tag generator and settings pages: spool rings in
filament colour, live job card (progress and time left read from CC2
Control's /api/printer while a job runs), log page with filters, iOS-style
settings with a write/dry-run switch. On phones: bottom tab bar, printer
switcher, slot details in a bottom sheet. Dark mode follows the system.
Web app manifest and home screen icons for "Add to Home Screen".

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014GcEk5tkfFSYD6NTF66NkC

tests/test_web.py

@@ -28,11 +28,20 @@ def make_client(tmp_path, env=None):
 
 def test_pages_render(tmp_path):
     c, _ = make_client(tmp_path)
-    for path in ("/", "/tags", "/settings"):
+    for path in ("/", "/log", "/tags", "/settings"):
         r = c.get(path)
         assert r.status_code == 200 and "CC2" in r.text
 
 
+def test_web_app_files(tmp_path):
+    c, _ = make_client(tmp_path)
+    m = c.get("/manifest.webmanifest")
+    assert m.status_code == 200 and m.json()["display"] == "standalone"
+    for icon in m.json()["icons"]:
+        assert c.get(icon["src"]).status_code == 200
+    assert c.get("/static/icon-180.png").headers["content-type"] == "image/png"
+
+
 def test_writes_need_marker_header(tmp_path):
     c, _ = make_client(tmp_path)
     assert c.post("/api/settings", json={"dry_run": False}).status_code == 403