test(ui): five verification rounds, and two things they found

Five rounds, each looking from an angle the previous one cannot:

  1. text     — every "Thay đổi" bullet on the page vs a probe (existing)
  2. geometry — check_layout_geometry.py: reading order of the rail, section
                order down Monitoring, which side each pane is on, and the size
                relationships the design names (hero card, 26px dot)
  3. inventory— check_controls_alive.py: every control in controls.json still
                present in the built app, attributed to its owning CLASS via the
                baseline commit (a file holds several classes, so a per-file
                check reported eight dialog controls as missing)
  4. eyes     — rendered screens read against the wireframes
  5. adversarial — check_probes_bite.py: break one feature at a time and fail if
                the matching check still passes

What rounds 4 and 5 caught, which 1-3 could not:

  * Schedule showed six of seven lanes; the seventh needed a horizontal
    scroll. The design says "giữ đủ 7 lane, thu hẹp cho vừa một màn". Lane
    minimum width 190 → 150, so 7 × 150 + gaps fits a 1280 window. Round 2 now
    measures this instead of relying on someone noticing.

  * check_design_parity ALWAYS returned 0. It was a report, not a check: every
    probe in it was incapable of failing, so a regression would print on screen
    and still exit green. It now exits non-zero when anything is CHUA — which
    is what let round 5 detect the two mutations it had been sleeping through.

Also fixed in the harness itself: it rewrote line endings while restoring
mutated files (read_text/write_text translate both ways), and it compared the
tree against "clean" rather than against its own starting state.

All ten checkers green by exit code.

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

tools/check_probes_bite.py

@@ -0,0 +1,130 @@
+"""Round 5: do the checks actually bite?
+
+Rounds 1–4 all report green. That is only worth something if the checks would
+have turned red had the work not been done. So this round breaks the app on
+purpose, one feature at a time, and fails if the corresponding check still
+passes — a check that cannot fail is not evidence.
+
+Each mutation is applied by monkey-patching the module BEFORE the checker
+builds its own window, then undone.
+
+Run:  python tools/check_probes_bite.py
+"""
+from __future__ import annotations
+
+import io
+import os
+import runpy
+import subprocess
+import sys
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parent.parent
+sys.path.insert(0, str(REPO.parent))
+sys.path.insert(0, str(Path(__file__).resolve().parent))
+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",
+     "check_layout_geometry.py"),
+    ("tra lane Running ve khong vien",
+     "ui/schedule_task_tab.py",
+     'if status == "running" and counts[status]:',
+     'if False:',
+     "check_design_parity.py"),
+    ("bo cot muc luc cua Cai dat",
+     "ui/settings_dialog.py",
+     "self.section_list, self.section_stack = section_panels(pages)",
+     "self.section_list, self.section_stack = section_panels(pages[:1])",
+     "check_dialogs.py"),
+    ("noi lai dai tab flow Co4E",
+     "ui/co4e_tab.py",
+     "self.flow_scroll.setVisible(False)",
+     "self.flow_scroll.setVisible(True)",
+     "check_co4e.py"),
+    ("bo dong 'Tat ca project...' khoi GAN DAY",
+     "app.py",
+     'more.setData(0, Qt.UserRole, {"all": True})',
+     'more.setData(0, Qt.UserRole, {})',
+     "check_design_parity.py"),
+    ("tra thanh menu ve accordion (bo nhom day)",
+     "app.py",
+     'rows.append((self.nav_bottom, self._ROW_DASHBOARD, None,',
+     'rows.append((self.nav, self._ROW_DASHBOARD, None,',
+     "check_layout_geometry.py"),
+]
+
+
+def run_checker(script: str) -> int:
+    """Run a checker in a fresh process; return its exit code."""
+    proc = subprocess.run(
+        [sys.executable, str(REPO / "tools" / script)],
+        cwd=REPO, capture_output=True, text=True, encoding="utf-8",
+        errors="replace", env={**os.environ, "QT_QPA_PLATFORM": "offscreen",
+                               "PYTHONIOENCODING": "utf-8"})
+    return proc.returncode
+
+
+def tree_state() -> str:
+    return subprocess.run(["git", "status", "--short"], cwd=REPO,
+                          capture_output=True, text=True).stdout.strip()
+
+
+def main() -> int:
+    fails: list[str] = []
+    # Compare the tree BEFORE and AFTER, not against a clean tree: work in
+    # progress is legitimately uncommitted, and demanding a clean tree made this
+    # round fail for a reason that has nothing to do with the mutations.
+    before = tree_state()
+    print(f"{'hong gi':44} {'phep do':26} ket qua")
+    print("-" * 88)
+    for name, rel, find, repl, checker in MUTATIONS:
+        path = REPO / rel
+        # newline="" both ways: the default translates on read AND write, so a
+        # LF file came back as CRLF and every mutated file was left "modified"
+        # even after being restored.
+        with io.open(path, "r", encoding="utf-8", newline="") as fh:
+            original = fh.read()
+        if find not in original:
+            fails.append(f"{name}: khong tim thay doan can sua trong {rel}")
+            print(f"{name:44} {checker:26} *** KHONG AP DUNG DUOC ***")
+            continue
+
+        def write(text: str) -> None:
+            with io.open(path, "w", encoding="utf-8", newline="") as fh:
+                fh.write(text)
+
+        write(original.replace(find, repl, 1))
+        try:
+            code = run_checker(checker)
+        finally:
+            write(original)                                # always restore
+        bit = code != 0
+        print(f"{name:44} {checker:26} {'BAT DUOC' if bit else '*** KHONG BAT ***'}")
+        if not bit:
+            fails.append(f"{name}: {checker} van bao xanh du da lam hong")
+
+    # Everything must be back exactly as it was before this run.
+    after = tree_state()
+    same = after == before
+    print()
+    print("cay lam viec sau khi thu giong het truoc:", "co" if same else "*** KHAC ***")
+    if not same:
+        print("   truoc:", before.replace("\n", " | ") or "(sach)")
+        print("   sau  :", after.replace("\n", " | ") or "(sach)")
+        fails.append("file chua duoc khoi phuc sau khi thu")
+
+    print()
+    if fails:
+        print("*** VONG 5 THAT BAI ***")
+        for f in fails:
+            print("   " + f)
+        return 1
+    print(f"KET QUA VONG 5: ca {len(MUTATIONS)} phep do deu bat duoc loi khi co tinh lam hong")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())