Improve code organization and documentation (#325)

* Add MARK headers to improve code organization in major files

* Reorganize peer management functions in BluetoothMeshService

- Removed duplicate getCurrentPeerID(for:) function
- Consolidated peer identity functions in Peer Identity Mapping section
- Moved getPeerFingerprint(), getFingerprint(for:), isPeerIDOurs() to proper location
- Moved getCurrentPeerIDForFingerprint() and getCurrentPeerIDs() from Message Sending section
- Moved notifyPeerIDChange() to Peer Management section

* Consolidate peer management functions in BluetoothMeshService

- Moved getCachedPublicKey() and getCachedSigningKey() from Identity Cache Methods to Peer Connection Management
- Moved getPeerNicknames() and getPeerRSSI() to Peer Connection Management section
- Moved getAllConnectedPeerIDs(), notifyPeerListUpdate(), and cleanupStalePeers() to Peer Connection Management
- Removed duplicate function declarations after consolidation
- Improved code organization by grouping all peer-related functions together

* Consolidate message handling functions in ChatViewModel

- Moved handleHandshakeRequest() from floating location to Message Reception section
- Moved trimMessagesIfNeeded() and trimPrivateChatMessagesIfNeeded() to Message Batching section
- Improved code organization by grouping related message handling functions together
- Removed unnecessary comments from trim functions

* Improve ContentView organization with better documentation

- Added descriptive comments for complex inline computations
- Documented message extraction logic for private vs public chats
- Documented peer data computation and sorting logic
- Improved code readability by explaining complex operations inline
- Note: Attempted to extract complex computations into helper functions, but SwiftUI scope limitations made inline documentation a better approach

---------

Co-authored-by: jack <jackjackbits@users.noreply.github.com>

bitchat/Views/ContentView.swift

@@ -8,6 +8,8 @@
 
 import SwiftUI
 
+// MARK: - Supporting Types
+
 // Pre-computed peer data for performance
 struct PeerDisplayData: Identifiable {
     let id: String
@@ -19,6 +21,8 @@ struct PeerDisplayData: Identifiable {
     let encryptionStatus: EncryptionStatus
 }
 
+// MARK: - Lazy Link Preview
+
 // Lazy loading wrapper for link previews
 struct LazyLinkPreviewView: View {
     let url: URL
@@ -44,7 +48,11 @@ struct LazyLinkPreviewView: View {
     }
 }
 
+// MARK: - Main Content View
+
 struct ContentView: View {
+    // MARK: - Properties
+    
     @EnvironmentObject var viewModel: ChatViewModel
     @State private var messageText = ""
     @State private var textFieldSelection: NSRange? = nil
@@ -66,6 +74,8 @@ struct ContentView: View {
     @State private var scrollThrottleTimer: Timer?
     @State private var autocompleteDebounceTimer: Timer?
     
+    // MARK: - Computed Properties
+    
     private var backgroundColor: Color {
         colorScheme == .dark ? Color.black : Color.white
     }
@@ -78,6 +88,8 @@ struct ContentView: View {
         colorScheme == .dark ? Color.green.opacity(0.8) : Color(red: 0, green: 0.5, blue: 0).opacity(0.8)
     }
     
+    // MARK: - Body
+    
     var body: some View {
         GeometryReader { geometry in
             ZStack {
@@ -221,10 +233,13 @@ struct ContentView: View {
         }
     }
     
+    // MARK: - Message List View
+    
     private func messagesView(privatePeer: String?) -> some View {
         ScrollViewReader { proxy in
             ScrollView {
                 VStack(alignment: .leading, spacing: 0) {
+                    // Extract messages based on context (private or public chat)
                     let messages: [BitchatMessage] = {
                         if let privatePeer = privatePeer {
                             let msgs = viewModel.getPrivateChatMessages(for: privatePeer)
@@ -355,6 +370,8 @@ struct ContentView: View {
         }
     }
     
+    // MARK: - Input View
+    
     private var inputView: some View {
         VStack(spacing: 0) {
             // @mentions autocomplete
@@ -544,11 +561,15 @@ struct ContentView: View {
         }
     }
     
+    // MARK: - Actions
+    
     private func sendMessage() {
         viewModel.sendMessage(messageText)
         messageText = ""
     }
     
+    // MARK: - Sidebar View
+    
     private var sidebarView: some View {
         HStack(spacing: 0) {
             // Grey vertical bar for visual continuity
@@ -594,6 +615,7 @@ struct ContentView: View {
                                 .foregroundColor(secondaryTextColor)
                                 .padding(.horizontal)
                         } else {
+                            // Extract peer data for display
                             let peerNicknames = viewModel.meshService.getPeerNicknames()
                             let peerRSSI = viewModel.meshService.getPeerRSSI()
                             let myPeerID = viewModel.meshService.myPeerID
@@ -939,6 +961,8 @@ struct ContentView: View {
     
 }
 
+// MARK: - Helper Views
+
 // Helper view for rendering message content with clickable hashtags
 struct MessageContentView: View {
     let message: BitchatMessage
@@ -993,6 +1017,8 @@ struct MessageContentView: View {
             .textSelection(.enabled)
     }
     
+    // MARK: - Helper Methods
+    
     private func buildTextSegments() -> [(text: String, type: String)] {
         var segments: [(text: String, type: String)] = []
         let content = message.content
@@ -1052,6 +1078,8 @@ struct DeliveryStatusView: View {
     let status: DeliveryStatus
     let colorScheme: ColorScheme
     
+    // MARK: - Computed Properties
+    
     private var textColor: Color {
         colorScheme == .dark ? Color.green : Color(red: 0, green: 0.5, blue: 0)
     }
@@ -1060,6 +1088,8 @@ struct DeliveryStatusView: View {
         colorScheme == .dark ? Color.green.opacity(0.8) : Color(red: 0, green: 0.5, blue: 0).opacity(0.8)
     }
     
+    // MARK: - Body
+    
     var body: some View {
         switch status {
         case .sending: