fix(test): recover pace caret after word generation gaps (@anuragkej)

[anuragkej]

Description

This PR fixes a pace-caret edge case triggered with Plus Three (and similar dynamic word generation scenarios):

• keeps pace-caret state when it briefly runs past words that are not generated yet,
• retries safely while additional words may still be generated,
• stops retries cleanly when word exhaustion is terminal (to avoid an endless hidden-caret timer loop),
• adds targeted unit coverage for both recovery and terminal-stop paths.

Supersedes #7559 (GitHub would not allow reopening it after the source repo was detached from fork network).

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Closes #7527

[Copilot]

Pull request overview

Fixes an edge case where the pace caret can disappear when it advances into yet-to-be-generated words (e.g., Plus Three), by adding a safe retry mechanism and a terminal stop condition to avoid endless hidden-caret loops.

Changes:

• Update pace-caret stepping to retain state on “out of words” and retry updates while more words may still be generated.
• Stop retrying (and clear pace-caret settings) when word generation is terminal for the current mode/limits.
• Add Vitest unit coverage for the recovery and terminal-stop behaviors.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
frontend/src/ts/test/pace-caret.ts	Adds retry scheduling + terminal exhaustion detection; refactors stepping to return success/failure.
frontend/__tests__/test/pace-caret.spec.ts	Adds targeted tests around recovery vs terminal-stop behavior.

[Copilot]

areAllTestWordsGenerated() duplicates TestLogic.areAllTestWordsGenerated() logic (frontend/src/ts/test/test-logic.ts:572-590). This risks drift if generation/limit rules change. Consider extracting this predicate into a small shared module (importable by both) or otherwise centralizing it so pace-caret and test-logic stay consistent.

[Copilot]

This recovery test doesn’t exercise the new timer-based retry path: it manually calls PaceCaret.update(0) again after pushing a word, instead of letting the scheduled retry fire. To validate the fix end-to-end, assert a retry timer was scheduled after the first failure and then advance/run fake timers (and flush pending promises) to confirm the caret state recovers via the scheduled update.

Suggested change

	await PaceCaret.update(0);
	expect(vi.getTimerCount()).toBeGreaterThan(0);
	await vi.runOnlyPendingTimersAsync();
	await Promise.resolve();