Remove dead code found by full Periphery audit; add scan config + advisory CI (#1410)

Periphery 3.7.4 audit of both schemes (macOS + iOS, intersected so
platform-specific code is never touched), with test targets indexed and
the share extension built. 277 dead declarations removed or demoted:
dead forwarding wrappers (ChatViewModel+Nostr/+PrivateChat), removed-
feature remnants (autocomplete command suggestions, back-swipe tuning,
MediaSendError, GeohashParticipantTracker), unused Tor dormancy
bindings, assign-only properties, unused parameters (renamed to _), and
redundant public accessibility. 13 orphaned localization keys deleted
across all 29 locales (old pre-#1392 location-notes UI, app_info
warnings).

Two real tests were flagged as unused because they never ran: Swift
Testing methods missing @Test (NostrProtocolTests.
testAckRoundTripNIP44V2_Delivered, NotificationStreamAssemblerTests.
testAssemblesCompressedLargeFrame). Re-armed both; they pass.

Deliberately kept, now recorded in .periphery.baseline.json: iOS-only
code invisible to the CI macOS scan, C FFI signatures, keep-alive
NWPathMonitor reference, InboundEventKey.eventID (dedup semantics),
wifiBulk capability bit (reserved for Wi-Fi bulk work, used by
BitFoundation package tests), and the String secureClear cluster
(exercised by package tests).

New: .periphery.yml config and an advisory Dead Code CI job (mirrors
the SwiftLint precedent from #1361) that fails on findings not in the
committed baseline.

Verified: full macOS app suite, BitFoundation (119) and BitLogger (13)
package tests green; periphery scan --strict exits clean.

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

bitchat/ViewModels/ChatViewModel.swift

@@ -84,7 +84,6 @@ import SwiftUI
 import Combine
 import CommonCrypto
 import CoreBluetooth
-import Tor
 #if os(iOS)
 import UIKit
 #endif
@@ -222,12 +221,6 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
         conversations.unreadDirectRoutingPeerIDs()
     }
 
-    /// Check if there are any unread messages (including from temporary Nostr peer IDs)
-    @MainActor
-    var hasAnyUnreadMessages: Bool {
-        !unreadPrivateMessages.isEmpty
-    }
-
     /// Open the most relevant private chat when tapping the toolbar unread icon.
     /// Prefers the most recently active unread conversation, otherwise the most recent PM.
     @MainActor
@@ -245,20 +238,6 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
         set { peerIdentityStore.setSelectedPrivateChatFingerprint(newValue) }
     }
 
-    // Resolve full Noise key for a peer's short ID (used by UI header rendering)
-    @MainActor
-    private func getNoiseKeyForShortID(_ shortPeerID: PeerID) -> PeerID? {
-        if let mapped = peerIdentityStore.stablePeerID(forShortID: shortPeerID) { return mapped }
-        // Fallback: derive from active Noise session if available
-        if shortPeerID.id.count == 16,
-           let key = meshService.noiseSessionPublicKeyData(for: shortPeerID) {
-            let stable = PeerID(hexData: key)
-            peerIdentityStore.setStablePeerID(stable, forShortID: shortPeerID)
-            return stable
-        }
-        return nil
-    }
-
     // Resolve short mesh ID (16-hex) from a full Noise public key hex (64-hex)
     @MainActor
     func getShortIDForNoiseKey(_ fullNoiseKeyHex: PeerID) -> PeerID {
@@ -354,18 +333,11 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
 
     // MARK: - Social Features (Delegated to PeerStateManager)
 
-    @MainActor
-    var favoritePeers: Set<String> { unifiedPeerService.favoritePeers }
     @MainActor
     var blockedUsers: Set<String> { unifiedPeerService.blockedUsers }
 
     // MARK: - Encryption and Security
 
-    // Noise Protocol encryption status
-    var peerEncryptionStatus: [PeerID: EncryptionStatus] {
-        get { peerIdentityStore.encryptionStatuses }
-        set { peerIdentityStore.replaceEncryptionStatuses(newValue) }
-    }
     var verifiedFingerprints: Set<String> {
         get { peerIdentityStore.verifiedFingerprints }
         set { peerIdentityStore.setVerifiedFingerprints(newValue) }
@@ -959,11 +931,6 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
 
     // MARK: - Public helpers
 
-    /// Published geohash people list for SwiftUI observation
-    var geohashPeople: [GeoPerson] {
-        participantTracker.visiblePeople
-    }
-
     /// Return the current, pruned, sorted people list for the active geohash without mutating state.
     @MainActor
     func visibleGeohashPeople() -> [GeoPerson] {
@@ -1056,14 +1023,6 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
         publicConversationCoordinator.displayNameForNostrPubkey(pubkeyHex)
     }
 
-    // MARK: - Media Transfers
-
-    private enum MediaSendError: Error {
-        case encodingFailed
-        case tooLarge
-        case copyFailed
-    }
-
     func currentPublicSender() -> (name: String, peerID: PeerID) {
         publicConversationCoordinator.currentPublicSender()
     }
@@ -1125,7 +1084,7 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
     }
 
     @MainActor
-    @objc func handlePeerStatusUpdate(_ notification: Notification) {
+    @objc func handlePeerStatusUpdate(_: Notification) {
         peerIdentityCoordinator.handlePeerStatusUpdate()
     }
 
@@ -1159,15 +1118,6 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
         lifecycleCoordinator.markPrivateMessagesAsRead(from: peerID)
     }
 
-    func getMessages(for peerID: PeerID?) -> [BitchatMessage] {
-        lifecycleCoordinator.getMessages(for: peerID)
-    }
-
-    @MainActor
-    func getPrivateChatMessages(for peerID: PeerID) -> [BitchatMessage] {
-        lifecycleCoordinator.getPrivateChatMessages(for: peerID)
-    }
-
     @MainActor
     func getPeerIDForNickname(_ nickname: String) -> PeerID? {
         peerIdentityCoordinator.getPeerIDForNickname(nickname)