DMs to unreachable peers use store-and-forward instead of failing instantly (#1415)

* DMs to unreachable peers route through store-and-forward; drop stale reachability gates

Field-found: sendPrivateMessage pre-judged reachability and marked the
message failed without ever calling the router, so the retained outbox,
courier deposits, and bridge drops never ran — a DM composed after a
peer's reachability window lapsed was dead on arrival while an identical
one sent a minute earlier delivered. Messages now always route; a live
path earns "sent", everything else stays "sending" until the router
reports carried/delivered or expires it as failed.

A sweep for sibling gates found and fixed:
- startPrivateChat refused offline non-mutual favorites ("mutual favorite
  required for offline messaging") — store-and-forward only needs the
  recipient's noise key, so the gate and its string are gone.
- markPrivateMessagesAsRead skipped the whole receipt pass for peers
  without a stored Nostr key, starving mesh-connected non-favorites; the
  router picks the transport now (sentReadReceipts dedups the parallel
  PrivateChatManager path).
- DM/geoDM blocked notices and the unknown-group error posted to the
  active public timeline; they now land in the thread they're about via
  addLocalPrivateSystemMessage.
- Banned copy: literal "user" fallbacks in code become "anon" (the
  default-nickname convention), and es/fr/it/pt translations of four keys
  still saying usuario/utilisateur/utente/usuário now say person. Orphaned
  keys removed (system.dm.unreachable, content.delivery.reason.unreachable,
  system.chat.requires_favorite).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Deflake BLEServiceCoreTests: longTimeout for positive waits

CI flaked on duplicatePacket_isDeduped: the first message landed after the
5s wait expired on a loaded runner (the test's later count==1 assertions
passed, proving late delivery, not lost delivery). All four positive waits
in the file now use TestConstants.longTimeout, which exists for exactly
this — waitUntil returns as soon as the condition holds, so passing runs
never pay the longer ceiling.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Fix read-receipt test contamination; baseline Periphery noiseKey flake

Two CI failures, both environmental:

- markReadReceiptSent_returnsFalseOnSecondCall flaked because every test
  ChatViewModel shared one per-process read-receipts scratch suite; the
  lifecycle test persists the same "read-1" ID (a path the receipt-gate
  removal now reaches), and test order decided who saw whose state. Each
  instance now gets its own UUID-suffixed suite.

- Periphery intermittently misses the loadFromDisk read of
  PrekeyBundleStore.StoredBundle.noiseKey and fails --strict with a false
  "assign-only" finding (recurrence of a known flake). Its USR is
  baselined; an in-source periphery:ignore can't work because strict mode
  flags it as superfluous on runs where the indexer gets it right.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: jack <jackjackbits@users.noreply.github.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

bitchatTests/ChatLifecycleCoordinatorContextTests.swift

@@ -328,7 +328,7 @@ struct ChatLifecycleCoordinatorContextTests {
         #expect(context.ownerLevelReadPasses == [peerID])
     }
     @Test @MainActor
-    func markPrivateMessagesAsRead_routesReceiptsOnlyForNostrReachableFavorites() {
+    func markPrivateMessagesAsRead_routesReceiptsForFavoritesAndNonFavorites() {
         let context = MockChatLifecycleContext()
         let coordinator = ChatLifecycleCoordinator(context: context)
         let noiseKey = Data(repeating: 0xAB, count: 32)
@@ -351,12 +351,15 @@ struct ChatLifecycleCoordinatorContextTests {
         #expect(context.routedReadReceipts.map(\.peerID) == [peerID])
         #expect(context.sentReadReceipts.contains("in-1"))
 
-        // No favorite relationship (no Nostr key): the receipt pass is skipped.
+        // No favorite relationship: receipts still route — the router picks
+        // whatever transport can reach the peer (mesh included). Gating on a
+        // stored Nostr key silently starved mesh-connected non-favorites.
         let otherKey = Data(repeating: 0xCD, count: 32)
         let otherPeer = PeerID(hexData: otherKey)
         context.privateChats[otherPeer] = [makePrivateMessage(id: "in-2", senderPeerID: otherPeer)]
         coordinator.markPrivateMessagesAsRead(from: otherPeer)
-        #expect(context.routedReadReceipts.map(\.messageID) == ["in-1"])
+        #expect(context.routedReadReceipts.map(\.messageID) == ["in-1", "in-2"])
+        #expect(context.sentReadReceipts.contains("in-2"))
     }
 
 }