Make peer lists accessible and actionable; block mesh peers by stable identity (#1360)

* Make peer lists accessible and actionable; block by stable identity

Who you can reach — the app's most important fact — was encoded in
unlabeled 10pt icons with macOS-only tooltips, and the mesh list had no
actions (block/favorite/verify were slash-command-only).

- Both peer lists become real accessibility citizens: each row is one
  element announcing name, reachability, and favorite/unread/blocked
  state, with a button trait and custom actions for the gesture-only
  interactions. Neither file previously had a single accessibility
  modifier. Reachability icons gain tooltips reusing existing strings;
  teleported vs in-area pins are explained.
- Mesh rows gain the context menu the geohash list already had: direct
  message, favorite, show fingerprint, block/unblock. The fingerprint
  double-tap, previously shadowed by the single tap, is reordered so it
  fires.
- The DM header's offline state (previously EmptyView — absence of a
  glyph as the only signal) becomes a dimmed "offline" tag, and a
  geohash DM — always Nostr-routed — no longer mislabels itself
  "offline".
- App Info gains a SYMBOLS legend defining every glyph the lists and
  headers use; nothing defined them before.
- Mesh block/unblock now resolve by the peer's stable Noise identity
  instead of a `/block <displayName>` string, so the exact tapped row is
  affected and offline peers can be unblocked (with covering tests).

New strings are added source-language (en) only.

* Surface block/unblock feedback in the conversation where it was triggered

setMeshPeerBlocked silently returned when the peer's identity could not
be resolved (e.g. long-press-blocking an old public message from a
sender who left and was never a favorite), where the /block command
printed "cannot block X: not found or unable to verify identity" — post
that same message from the guard branch.

Both the failure and confirmation messages now route through
addCommandOutput instead of addSystemMessage, so blocking from inside a
private chat prints into that chat rather than invisibly into the
public timeline (same routing #1363 applied to command output).

The confirmation also reuses the /block wording ("blocked X. you will
no longer receive messages from them") for parity with the command.

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

* Remove dead accessibility label and unreachable /unblock fallback

The favorite button's .accessibilityLabel in MeshPeerList is
unreachable: the row-level .accessibilityElement(children: .ignore)
swallows child elements, and the row's custom accessibility action
already covers favoriting.

ConversationUIModel.unblock is only called from the mesh peer list with
a non-optional mesh peerID, so the "/unblock <name>" fallback branch
could never run — take PeerID directly and drop the branch.

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

---------

Co-authored-by: jack <212554440+jackjackbits@users.noreply.github.com>
Co-authored-by: jack <jackjackbits@users.noreply.github.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

bitchat/Services/UnifiedPeerService.swift

@@ -257,7 +257,29 @@ final class UnifiedPeerService: ObservableObject, TransportPeerEventsDelegate {
         
         return false
     }
-    
+
+    /// Block or unblock a mesh peer by its stable Noise identity.
+    ///
+    /// The block is keyed by the peer's fingerprint, resolved from `peerID`
+    /// (cache / mesh session / known-peer Noise key). This works even when the
+    /// peer is offline — including offline favorites — so the exact tapped peer
+    /// is (un)blocked unambiguously instead of being re-resolved by a
+    /// display-name string that two peers could share.
+    /// - Returns: the resolved fingerprint, or `nil` if the identity is unknown.
+    @discardableResult
+    func setBlocked(_ peerID: PeerID, blocked: Bool) -> String? {
+        guard let fingerprint = getFingerprint(for: peerID) else {
+            SecureLogger.warning(
+                "⚠️ Cannot \(blocked ? "block" : "unblock") - unknown identity for peer: \(peerID)",
+                category: .session
+            )
+            return nil
+        }
+        identityManager.setBlocked(fingerprint, isBlocked: blocked)
+        updatePeers()
+        return fingerprint
+    }
+
     /// Toggle favorite status
     func toggleFavorite(_ peerID: PeerID) {
         guard let peer = getPeer(by: peerID) else {