Investigate: a synced library replacing data.json once didn't reach the view (e2e timeout) #477

An e2e run once timed out at tests/e2e/sync-persistence.test.ts:370, "keeps a new device's change when the library replaces its data.json". The view stayed on the first-run screen while data.json on disk already held the synced library.

Seen in: the V-475 verification (Obsidian 1.14.4, Linux, fresh vault, PR #475 head d2c2bff). In that first full run, 189 tests passed and this one timed out. The same test passed in isolation on both #475's head and master, and a second full fresh-vault run passed 190/190. Runtime error journals were empty.

Why it matters: if PodNotes sometimes misses an external data.json change (sync replacing the library) on a new device, the device keeps showing an empty library until something else triggers a reload. That's the multi-device flow 2.22.0 is built around (#388, #398). Root cause and any real-user impact are unproven.

Evidence: the screenshot, data.json, DOM, notices and console messages are preserved in the program store under evidence/V-475/full-suite-sync-timeout/ (coordinator machine).

Next step: run the journey in a loop under full-suite load. If it reproduces, check whether onExternalSettingsChange or the vault watcher fired, and whether the view re-reads the library after adoption.