Fix confirmation overlay not closing properly when errors occur (#120)

* Address code review comments on save-draft-project draft persistence

- Move setPendingReplace(undefined) into finally in handleConfirmReplace so
  the DiscardDraftConfirm dialog always dismisses even if a future refactor
  makes openProject or startNewDraft throwable
- Add comments documenting the fire-and-forget persistence design and its
  failure-visibility trade-offs (dirty flag set optimistically, backend
  notification as the sole user signal)
- Add comment on the transient stale dirty indicator when sourceProjectId
  changes mid-load (self-corrects; nearly unreachable in practice)
- Add comment explaining why getDraftSnapshot is called at render time in
  ProjectModals (ref read is allocation-free; only consumed by saveAs branch)
- Add comment clarifying that per-row Overwrite buttons open the inline
  confirmation dialog rather than triggering a save

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* Nix less-important comments

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: imnasnainaec

src/components/modals/ProjectModals.tsx

@@ -270,8 +270,8 @@ export default function ProjectModals({
       }
     } finally {
       setIsReplacing(false);
+      setPendingReplace(undefined);
     }
-    setPendingReplace(undefined);
   }, [isReplacing, openProject, pendingReplace, startNewDraft]);
 
   /** Cancels the deferred action, returning to the underlying modal with the draft untouched. */

src/hooks/useDraftProject.ts

@@ -135,6 +135,13 @@ export default function useDraftProject(
    * Persists `draft` to storage, fire-and-forget. The backend surfaces an error notification on
    * failure; here we only log so a rejected write never throws into a render or event handler.
    *
+   * Note: the draft is the **only** persistence path — there is no secondary write on blur or
+   * unmount that would retry a failed autosave. If storage is unavailable during editing, the
+   * backend sends one error notification per failed write; if that notification itself fails (the
+   * `.catch(() => {})` in `main.ts`), edits made in that window are silently lost on the next page
+   * refresh. The tab title's `●` marker stays lit because `dirty` is set optimistically before the
+   * write, not in response to its outcome.
+   *
    * @param draft - The draft envelope to write.
    */
   const persist = useCallback(