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/Services/BLE/BLEFragmentAssemblyBuffer.swift

@@ -61,7 +61,6 @@ struct BLEFragmentAssemblyBuffer {
     }
 
     private struct Metadata {
-        let type: UInt8
         let total: Int
         let timestamp: Date
         let isBroadcast: Bool
@@ -150,7 +149,6 @@ struct BLEFragmentAssemblyBuffer {
 
         fragmentsByKey[header.key] = [:]
         metadataByKey[header.key] = Metadata(
-            type: header.originalType,
             total: header.total,
             timestamp: now,
             isBroadcast: header.isBroadcastFragment,

bitchat/Services/BLE/BLELogRateLimiter.swift

@@ -25,9 +25,4 @@ final class BLELogRateLimiter {
         }
     }
 
-    func removeAll() {
-        queue.sync {
-            lastLogTimeByKey.removeAll()
-        }
-    }
 }

bitchat/Services/BLE/BLEOutboundPacketPolicy.swift

@@ -20,7 +20,7 @@ enum BLEOutboundPacketPolicy {
         }
     }
 
-    static func priority(for packet: BitchatPacket, data: Data) -> BLEOutboundWritePriority {
+    static func priority(for packet: BitchatPacket, data _: Data) -> BLEOutboundWritePriority {
         guard let messageType = MessageType(rawValue: packet.type) else { return .low }
         switch messageType {
         case .fragment:

bitchat/Services/BLE/BLEPeerRegistry.swift

@@ -141,14 +141,6 @@ struct BLEPeerRegistry {
         }
     }
 
-    func collisionResolvedNickname(for peerID: PeerID, selfNickname: String) -> String? {
-        guard let info = peers[peerID], info.isVerifiedNickname else { return nil }
-        let hasCollision = peers.values.contains {
-            $0.isConnected && $0.nickname == info.nickname && $0.peerID != peerID
-        } || selfNickname == info.nickname
-        return hasCollision ? info.nickname + "#" + String(peerID.id.prefix(4)) : info.nickname
-    }
-
     mutating func markDisconnected(_ peerID: PeerID) {
         guard var info = peers[peerID] else { return }
         info.isConnected = false

bitchat/Services/BLE/BLEService.swift

@@ -10,7 +10,6 @@ import UIKit
 /// BLEService — Bluetooth Mesh Transport
 /// - Emits events exclusively via `BitchatDelegate` for UI.
 /// - ChatViewModel must consume delegate callbacks (`didReceivePublicMessage`, `didReceiveNoisePayload`).
-/// - A lightweight `peerSnapshotPublisher` is provided for non-UI services.
 final class BLEService: NSObject {
     
     // MARK: - Constants
@@ -493,13 +492,6 @@ final class BLEService: NSObject {
     weak var delegate: BitchatDelegate?
     weak var eventDelegate: TransportEventDelegate?
     weak var peerEventsDelegate: TransportPeerEventsDelegate?
-    
-    // MARK: Peer snapshots publisher (non-UI convenience)
-    
-    private let peerSnapshotSubject = PassthroughSubject<[TransportPeerSnapshot], Never>()
-    var peerSnapshotPublisher: AnyPublisher<[TransportPeerSnapshot], Never> {
-        peerSnapshotSubject.eraseToAnyPublisher()
-    }
 
     func currentPeerSnapshots() -> [TransportPeerSnapshot] {
         collectionsQueue.sync {
@@ -1323,7 +1315,7 @@ final class BLEService: NSObject {
         }
     }
 
-    private func handleLeave(_ packet: BitchatPacket, from peerID: PeerID) {
+    private func handleLeave(_: BitchatPacket, from peerID: PeerID) {
         _ = collectionsQueue.sync(flags: .barrier) {
             // Remove the peer when they leave
             peerRegistry.remove(peerID)
@@ -2174,7 +2166,7 @@ extension BLEService: CBPeripheralDelegate {
         }
     }
 
-    private func processNotificationPacket(_ packet: BitchatPacket, from peripheral: CBPeripheral, peripheralUUID: String, receivedFrom peerID: PeerID) {
+    private func processNotificationPacket(_ packet: BitchatPacket, from _: CBPeripheral, peripheralUUID: String, receivedFrom peerID: PeerID) {
         let senderID = PeerID(hexData: packet.senderID)
 
         if packet.type != MessageType.announce.rawValue {
@@ -3422,7 +3414,7 @@ extension BLEService {
     /// Transport-level handling for a received nostrCarrier packet; policy
     /// (verification of the carried event, quotas, loop prevention) lives in
     /// `GatewayService` behind `onNostrCarrierPacket`.
-    private func handleNostrCarrier(_ packet: BitchatPacket, from peerID: PeerID) {
+    private func handleNostrCarrier(_ packet: BitchatPacket, from _: PeerID) {
         let senderID = PeerID(hexData: packet.senderID)
         let directedToUs: Bool
         if let recipientID = packet.recipientID {
@@ -4476,7 +4468,7 @@ extension BLEService {
     /// gossip backfill and hand the payload to the UI layer, where the group
     /// coordinator decrypts and authenticates against the roster. Non-members
     /// still relay (generic broadcast relay path) but never decode.
-    private func handleGroupMessage(_ packet: BitchatPacket, from peerID: PeerID) {
+    private func handleGroupMessage(_ packet: BitchatPacket, from _: PeerID) {
         let isBroadcastRecipient: Bool = {
             guard let recipient = packet.recipientID else { return true }
             return recipient.count == 8 && recipient.allSatisfy { $0 == 0xFF }
@@ -4636,8 +4628,6 @@ extension BLEService {
         let transportPeers: [TransportPeerSnapshot] = collectionsQueue.sync {
             peerRegistry.transportSnapshots(selfNickname: myNickname)
         }
-        // Notify non-UI listeners
-        peerSnapshotSubject.send(transportPeers)
         // Notify UI on MainActor via delegate
         Task { @MainActor [weak self] in
             self?.peerEventsDelegate?.didUpdatePeerSnapshots(transportPeers)