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/App/AppArchitecture.swift

@@ -36,34 +36,12 @@ enum AppEvent: Sendable, Equatable {
 actor AppEventStream {
     private var continuations: [UUID: AsyncStream<AppEvent>.Continuation] = [:]
 
-    func stream() -> AsyncStream<AppEvent> {
-        let id = UUID()
-        return AsyncStream { continuation in
-            continuations[id] = continuation
-            continuation.onTermination = { [id] _ in
-                Task {
-                    await self.removeContinuation(id)
-                }
-            }
-        }
-    }
-
     func emit(_ event: AppEvent) {
         for continuation in continuations.values {
             continuation.yield(event)
         }
     }
 
-    func finish() {
-        for continuation in continuations.values {
-            continuation.finish()
-        }
-        continuations.removeAll()
-    }
-
-    private func removeContinuation(_ id: UUID) {
-        continuations.removeValue(forKey: id)
-    }
 }
 
 /// Identity key for a direct conversation. Equality and hashing use the

bitchat/App/AppRuntime.swift

@@ -18,8 +18,6 @@ final class AppRuntime: ObservableObject {
     /// (docs/CONVERSATION-STORE-DESIGN.md). Owned here; the feature models
     /// and `ChatViewModel` observe and mutate it through its intent API.
     let conversations: ConversationStore
-    let peerIdentityStore: PeerIdentityStore
-    let locationPresenceStore: LocationPresenceStore
     let publicChatModel: PublicChatModel
     let privateInboxModel: PrivateInboxModel
     let privateConversationModel: PrivateConversationModel
@@ -51,8 +49,6 @@ final class AppRuntime: ObservableObject {
         let locationPresenceStore = LocationPresenceStore()
         let locationManager = LocationChannelManager.shared
         self.conversations = conversations
-        self.peerIdentityStore = peerIdentityStore
-        self.locationPresenceStore = locationPresenceStore
         self.chatViewModel = ChatViewModel(
             keychain: keychain,
             idBridge: idBridge,

bitchat/App/ConversationStore.swift

@@ -796,16 +796,6 @@ extension ConversationStore {
         return messageIDs
     }
 
-    /// Removes every direct conversation (panic clear).
-    func removeAllDirectConversations() {
-        let directIDs = conversationIDs.filter { id in
-            if case .direct = id { return true }
-            return false
-        }
-        for id in directIDs {
-            removeConversation(id)
-        }
-    }
 }
 
 // MARK: - Diagnostics support

bitchat/App/LocationChannelsModel.swift

@@ -1,4 +1,3 @@
-import BitFoundation
 import Combine
 import Foundation
 
@@ -17,7 +16,6 @@ final class LocationChannelsModel: ObservableObject {
     private let manager: LocationChannelManager
     private let network: NetworkActivationService
     private let gateway: GatewayService
-    private var cancellables = Set<AnyCancellable>()
 
     init(
         manager: LocationChannelManager? = nil,

bitchat/App/PeerIdentityStore.swift

@@ -25,10 +25,6 @@ final class PeerIdentityStore: ObservableObject {
         stablePeerIDsByShortID[peerID] = stablePeerID
     }
 
-    func replaceStablePeerIDs(_ mappings: [PeerID: PeerID]) {
-        stablePeerIDsByShortID = mappings
-    }
-
     func fingerprint(for peerID: PeerID) -> String? {
         peerFingerprintsByPeerID[peerID]
     }
@@ -94,10 +90,6 @@ final class PeerIdentityStore: ObservableObject {
         invalidateEncryptionCache(for: peerID)
     }
 
-    func replaceEncryptionStatuses(_ statuses: [PeerID: EncryptionStatus]) {
-        encryptionStatuses = statuses
-    }
-
     func setVerifiedFingerprints(_ fingerprints: Set<String>) {
         verifiedFingerprints = fingerprints
     }

bitchat/App/VerificationModel.swift

@@ -3,7 +3,6 @@ import Combine
 import Foundation
 
 struct FingerprintPresentationState: Equatable {
-    let statusPeerID: PeerID
     let peerNickname: String
     let encryptionStatus: EncryptionStatus
     let theirFingerprint: String?
@@ -56,10 +55,6 @@ final class VerificationModel: ObservableObject {
         return VerificationService.shared.buildMyQRString(nickname: currentNickname, npub: npub) ?? ""
     }
 
-    func beginQRVerification(with qr: VerificationService.VerificationQR) -> Bool {
-        chatViewModel.beginQRVerification(with: qr)
-    }
-
     func verifyScannedPayload(_ payload: String) -> VerificationScanOutcome {
         guard let qr = VerificationService.shared.verifyScannedQR(payload) else {
             return .invalid
@@ -110,7 +105,6 @@ final class VerificationModel: ObservableObject {
         }
 
         return FingerprintPresentationState(
-            statusPeerID: statusPeerID,
             peerNickname: peerNickname,
             encryptionStatus: encryptionStatus,
             theirFingerprint: theirFingerprint,