[BBYU26]

Part of #884. C9b-1a, the first half of C9b-1: the dialog that asks which occurrences of a repeating event you mean, built and tested but not shown yet. 3.148.9-alpha (renumbered from 3.148.8 on 21-10, when #959 moved onto #968). Stacked on #959: the base is chore/calendar-split-journal, and there's no closing link while the base isn't main.

What it builds

Backend (safe on its own):

• A one-off that became a repeating event in Google is refused in the gate (BecameRepeating). This covers opening it, saving it, deleting it and planning a change, and it comes before the existing Recurring reason, which stays.
• When a delete's choices find the occurrence changed in Google, PM lands Google's copy. It does the same at the send and in the one-event delete.
• A settle that leaves the change held answers partial_split with a note, so the notice keeps its buttons.
• One MISSING_CHOICE_OK gate for the three shells, with a test that reads the source.
• The words PM shows for repeating-event refusals no longer say "series", "split", "instance", "exception" or "master". A test walks every variant.

Frontend:

• saveChoices.ts: the rows, the default pick, warning lines and the repeat-day question.
• SaveChoicesDialog: built, not mounted.
• The useEventWrites store: choices, scoped saves and deletes, settling, and partial notices that outlive the Calendar tab.
• WriteNotices action buttons (Finish / Remove the new part / Check again).
• The copy in editReasons.

Nothing changes for you yet: repeating events stay read-only, and release builds still refuse scoped writes and settling. The one visible change is that a one-off turned repeating in Google now says so.

Decisions taken while you were away (recommendations from the spec)

1. Two PRs: this one, then C9b-1b, which lifts Recurring and mounts the dialog, so main never shows Edit on a repeating event without it.
2. No automatic Finish: every send stays something you pressed.
3. Only the selected row's warnings show, under the radios.

Reviews

• Round 1 (four lenses, each finding checked by a skeptic) kept five lows, all fixed:
  • a save's title defaulting to empty;
  • the dialog's late refusal not announced;
  • every notice wrapping;
  • a missing test;
  • the What's New wording.
• Round 2 kept one low: a settle's plain "busy" now says Google turned Finish away and PM put the event back.

Each guard was checked by breaking it and seeing a test fail.

Checks

The full just check passes at the tip: 2,105 Rust tests and 2,065 frontend tests.

🤖 Generated with Claude Code

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.