Feature/fsg gamma team ui fix (#3)

## Summary

What changed and why?

## Change Type

- [ ] Cowork feature
- [ ] Bug fix
- [x] Core AI contribution
- [ ] Test / hardening
- [ ] Performance
- [ ] Documentation

## Related Work

Cowork Task:

Core Repo: http://34.143.229.138/gitea-admin/fsg-ai-core-assets

Core AI Issue:

Core Task:

Related PR:

## Scope

What is intentionally included?

What is intentionally NOT included?

## Validation

- [ ] Unit tests
- [ ] Integration tests
- [ ] Manual verification
- [ ] Regression check

Commands / evidence:

## Security Impact

Permission / credential / network / customer data impact:

## Compatibility

- [ ] No breaking change
- [ ] Breaking change documented

## Reviewer Notes

Anything Cowork reviewers should pay attention to.

---------

Co-authored-by: Hiep Ha Van <hiephv3@fpt.com>
Co-authored-by: Nam Pham Dinh Thanh <nampdt@fpt.com>
Co-authored-by: Lam Hoang Van <lamhv7@fpt.com>
Co-authored-by: NamPDT <minhanhpkpro@gmail.com>
Reviewed-on: #3

tools/check_help_i18n.py

@@ -0,0 +1,80 @@
+"""The help panel must follow a language switch — transcript included.
+
+retranslate() re-labelled the chrome but not the rendered HTML transcript, so
+the greeting and the "AI Assistant" speaker label stayed in the language the
+panel happened to be built in.
+"""
+from __future__ import annotations
+
+import os
+import re
+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")
+
+from capture_screens import (  # noqa: E402
+    _apply_theme, _freeze_schedulers, _isolate_home, _load_fonts)
+
+
+def main() -> int:
+    sandbox = _isolate_home()
+    from PySide6.QtWidgets import QApplication
+
+    sys.stdout.reconfigure(encoding="utf-8")   # ja/vi text on a cp932 console
+    app = QApplication([])
+    _load_fonts()
+    _freeze_schedulers()
+    _apply_theme(app)
+
+    from cowork_local.config import CONFIG_DIR
+    assert str(sandbox) in str(CONFIG_DIR), f"isolation failed: {CONFIG_DIR}"
+
+    from seed_demo_data import seed
+    seed()
+
+    from cowork_local.app import MainWindow
+    from cowork_local.config import AppConfig
+    from cowork_local.i18n import set_language
+    from cowork_local.state import AppContext
+
+    set_language("vi")
+    win = MainWindow(AppContext(AppConfig.load()), user_name="local")
+    win.resize(1400, 900)
+    win.show()
+    app.processEvents()
+
+    panel = win.help_agent
+    fails = []
+    for lang in ("en", "ja", "vi"):
+        win._set_language(lang) if hasattr(win, "_set_language") else set_language(lang)
+        if not hasattr(win, "_set_language"):
+            panel.retranslate()
+        app.processEvents()
+
+        # The panel greets by the signed-in name, not the placeholder.
+        want = panel._greeting()
+        shown = re.sub("<[^>]+>", " ", panel.log.toHtml())
+        shown = " ".join(shown.split())
+        # compare on the stable half of the sentence, the name is substituted
+        probe = " ".join(want.split())[:28]
+        state = "ok" if probe and probe in shown else "MISSING"
+        print(f"{lang}: title={panel.title.text()!r} greeting={state}")
+        if state != "ok":
+            print(f"    muon: {probe!r}")
+            print(f"    thay: {shown[:160]!r}")
+        if state != "ok":
+            fails.append(f"{lang}: transcript still shows another language")
+
+    print()
+    print("PASS  panel follows the language" if not fails
+          else "\n".join(f"FAIL  {f}" for f in fails))
+    sys.stdout.flush()
+    os._exit(1 if fails else 0)
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())