fix(tui): address copilot follow-up review on PR #16732 (#16740)

- moveCursor(extend=true) now collapses to the bare cursor when the
  computed offset equals the existing anchor instead of leaving a
  zero-length sel. Without this, Shift+Left at col 0 / Shift+Home at
  start would silently hide the hardware cursor (selected truthy)
  without rendering any highlight.
- _tui_need_npm_install also catches UnicodeDecodeError so a corrupted
  / non-UTF8 lockfile falls back to the mtime path the docstring
  promises instead of crashing.

Made-with: Cursor

hermes_cli/main.py

@@ -868,7 +868,7 @@ def _tui_need_npm_install(root: Path) -> bool:
     try:
         wanted = json.loads(lock.read_text(encoding="utf-8")).get("packages") or {}
         installed = json.loads(marker.read_text(encoding="utf-8")).get("packages") or {}
-    except (OSError, json.JSONDecodeError):
+    except (OSError, UnicodeDecodeError, json.JSONDecodeError):
         return lock.stat().st_mtime > marker.stat().st_mtime
 
     def comparable(pkg: dict) -> dict: