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_bridge.py

@@ -759,3 +759,17 @@ def test_multicolour_print_books_each_roll(env):
     cc2.job = {"active": False}
     poll(env, 10)
     assert sorted(uses(env)) == [("use", 5, 6.0), ("use", 6, 3.0)]
+
+
+def test_job_progress_only_read_while_printing(env):
+    b = env["bridge"]
+    env["cc2"].print_info = None
+    poll(env)
+    assert b.snapshot["printers"][0]["job"] is None
+    env["cc2"].print_info = {"machine": {"progress": 40}, "print": {"current_layer": 12, "total_layers": 30, "remaining": 600}}
+    env["cc2"].job = {"active": True, "file": "/local/cube.gcode", "started": 1,
+                      "slots": [{"mm": 0, "grams": 0, "spool": ""}, {"mm": 330, "grams": 1.234, "spool": "s0001"}]}
+    poll(env)
+    job = b.snapshot["printers"][0]["job"]
+    assert job["file"] == "cube.gcode" and job["grams"] == 1.23 and job["slots"] == [{"slot": 1, "grams": 1.23}]
+    assert job["progress"] == 40 and job["layer"] == 12 and job["layers"] == 30 and job["remaining"] == 600