[desktop] Review virtual caret robustness gaps

[Codex]

Custom animated caret was added for the ProseMirror editor; review uncovered latent flaws that could break the cursor when multiple editors mount or when the plugin cannot attach its container.

• Findings

  • Module-scoped caret state (caret.ts caretStyle, activeView, activeEl) ties style updates to the last-mounted editor, so concurrent editors would fight over the cursor.
  • Plugin silently skips caret creation if view.dom lacks a parent, leaving the native cursor hidden and no visible caret.

• Recommended fixes

  • Scope caret element/state to each plugin instance; persist style per instance from localStorage.
  • Guard parent lookup with a fallback container or skip hiding the native caret when attachment fails; log for diagnostics.

• Illustrative snippet

  // Current shared state
  let caretStyle: CaretStyle = (localStorage.getItem("cursor") as CaretStyle) ?? "line";
  let activeView: EditorView | null = null;
  let activeEl: HTMLElement | null = null;

[greptile-apps]

No reviewable files after applying ignore patterns.