Tests shared a global CRDT singleton and content store HashMap, causing
flaky failures when parallel tests wrote items that polluted each
other's assertions. 3-5 random test failures per run.
Both CRDT_STATE and CONTENT_STORE now use thread_local! in test mode
so each test thread gets its own isolated instance. Production code
is unchanged — it still uses the global OnceLock singletons.
Also fixed 3 tests (create_story_writes_correct_content,
next_item_number_increments_from_existing_bugs,
next_item_number_scans_archived_too) that relied on leaked state
from other tests — they now write to the content store explicitly.
Result: 1902 passed, 0 failed across 5 consecutive runs.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
dave
eea54ca616