fix(notifications): read the tray with scope=all so read notifications stay in it

[Adron]

Summary

Closes #80.

scope=tray returns unread rows only and ignores limit, so the macOS tray emptied as you read it while the web bell retained recent history. A notification you glanced at simply vanished, with no way back to it.

The issue asked to probe before concluding anything. The probe found the cheap answer — candidate 1, not a backend ask.

The probe

?scope=tray            → 1 item   (the single unread one)
?scope=tray&limit=5    → 1 item   (limit ignored)
?scope=all&limit=3     → 3 items  (read and unread, newest first)
?scope=all&limit=10    → 10 items
?scope=all             → 20 items (the account's stored notificationTrayLimit)

unreadCount is returned under both scopes, so the badge is unaffected. Nothing folds into #58.

The change

1. Notifications.tray(scope:limit:) now defaults to "all". The unread-only scope stays reachable for anything that genuinely wants it — it is just not what the tray asks for.

2. The client-side prefix(limit) is deleted. It existed only because scope=tray ignored the parameter, and it made notificationTrayLimit appear to work while the rows it trimmed were unread-only — so the preference could only ever shrink an already-wrong list.

   It is deliberately not re-added as a belt-and-braces cap: a client-side trim over a correctly-limited response is invisible when it agrees with the server and wrong when it does not. There is a test pinning that choice.

3. Two stale notes that described scope=tray ignoring limit as a standing constraint are corrected — NotificationsEndpoint.swift and the G35 correction block in NotificationsService.swift.

No workaround of the kind the issue ruled out. Nothing fetches a wider page and filters client-side; the server does the limiting. That is the failure mode PR #69 fixed for the DM inbox.

On PR #73's notificationTrayLimit

That preference was close to inert against a route that ignored limit. It now works because the server honours it, rather than because the client hides rows after the fact.

Verification

• xcodebuild build → ** BUILD SUCCEEDED **
• xcodebuild test (App) → Executed 968 tests, with 0 failures · ** TEST SUCCEEDED **
• swift test InterlinedDomain → Executed 1014 tests, with 0 failures (was 1012)
• swift test InterlinedKit → NotificationsEndpointTests: Executed 12 tests, with 0 failures (was 9)
• swift test InterlinedPersistence → Executed 140 tests, with 0 failures

New tests, including the one that is the point of the whole change:

func test_givenAllRowsRead_whenLoadingTray_thenTheTrayStillShowsThem()
func test_givenTheServerOverAnswers_whenLoadingTray_thenRowsAreNotTrimmedClientSide()
func test_givenTheDefaultScope_whenBuildingTheTrayRequest_thenItIsReadInclusive()
func test_givenALimit_whenBuildingTheTrayRequest_thenItTravelsAlongsideTheScope()
func test_givenNoLimit_whenBuildingTheTrayRequest_thenTheParameterIsOmitted()

🤖 Generated with Claude Code

https://claude.ai/code/session_016gSWb3scYobtxLJioV1qF9