Double the assistant dot, and stop the checks measuring it against itself

26 → 52px, 14 → 28px for the sparkle. The audit page draws 26 ("26×26 · không
chữ, không chevron"); doubled at the user's request. Still half the area of the
84×64 button it replaced: 2704 vs 5376px².

Four checks pinned the old number. Three now read the size the design actually
claims rather than a literal — square, at least 24px to hit, and smaller than
what it replaced — and check_design_parity records the deviation in its item
label instead of scoring 52px against a 26px expectation.

The fourth attempt was worse than the literal: I had check_layout_geometry
import _DOT and compare against it, which makes it unfailable — change the
constant and the expectation moves too. check_probes_bite caught that, reporting
that doubling _DOT again left the checker green. It now bounds the range
(24..64, square), which the mutation does break.

24/24 checkers pass; check_multi_screen took the teardown segfault once in three
standalone runs.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

tools/check_probes_bite.py

@@ -18,7 +18,7 @@ import runpy
 import subprocess
 import sys␍
 
-sys.stdout.reconfigure(encoding="utf-8", errors="replace")
+sys.stdout.reconfigure(encoding="utf-8", errors="replace")
 from pathlib import Path
 
 REPO = Path(__file__).resolve().parent.parent
@@ -28,8 +28,8 @@ os.environ.setdefault("QT_QPA_PLATFORM", "offscreen")
 
 # (name, file, find, replace, checker that must FAIL because of it)
 MUTATIONS = [
-    ("bo cham tro ly 26px -> 64px",
-     "ui/help_agent_widget.py", "_DOT = 26", "_DOT = 64",
+    ("phong to cham tro ly gap doi khai bao",
+     "ui/help_agent_widget.py", "_DOT = 52", "_DOT = 104",
      "check_layout_geometry.py"),
     ("tra lane Running ve khong vien",
      "ui/schedule_task_tab.py",