Refactor/robustness (#446)

* Refactor BitChat for improved robustness and performance

Major refactoring to simplify architecture and fix critical issues:

Architecture Improvements:
- Replace complex BluetoothMeshService with simplified SimplifiedBluetoothService
- Consolidate message routing and peer management into unified services
- Remove redundant caching layers and optimize performance

Bug Fixes:
- Fix critical BLE peer mapping corruption in mesh networks
- Fix encrypted message routing failures in multi-peer scenarios
- Fix app freezes and Main Thread Checker warnings
- Fix BLE message delivery in dual-role connections
- Fix favorite toggle UI not updating instantly
- Fix Nostr offline messaging with 24-hour message filtering

Features:
- Add command processor for chat commands
- Add autocomplete service for mentions and commands
- Improve private chat management with dedicated service
- Add unified peer service for consistent state management

Performance:
- Optimize BLE reconnection speed
- Reduce excessive logging throughout codebase
- Improve message deduplication efficiency
- Optimize UI updates and state management

* Improvements refactor robust (#441)

* remove unused code

* remove more

* TLV for announcement

* restore

* restore

* restore?

* messages tlv too (#442)

* Fix Nostr notification and read receipt issues, add TLV encoding, cleanup unused code

## Notification & Read Receipt Fixes
- Fixed toolbar notification icon appearing incorrectly on app restart for already-read messages
- Fixed read receipts being incorrectly deleted on startup when privateChats was empty
- Fixed messages not being marked as read when opening chat for first time
- Fixed senderPeerID not being updated during message consolidation
- Added startup phase logic to block old messages (>30s) while allowing recent ones
- Fixed unread status checking across all storage locations (ephemeral, stable Noise keys, temporary Nostr IDs)

## TLV Encoding Implementation
- Implemented Type-Length-Value encoding for private message payloads
- Added PrivateMessagePacket struct with TLV encode/decode methods
- Enhanced message structure for better extensibility and robustness

## Code Cleanup
- Removed unused PeerStateManager class and related dependencies
- Removed dead protocol types (DeliveryAck, ProtocolAck/Nack, NoiseIdentityAnnouncement)
- Cleaned up BitchatDelegate by removing unused methods
- Removed excessive debug logging throughout ChatViewModel
- Added test-only ProtocolNack helper for integration tests

## Technical Details
- Messages stored under three ID types: ephemeral peer IDs, stable Noise key hexes, temporary Nostr IDs
- Fixed cleanupOldReadReceipts() to skip when privateChats is empty or during startup
- Updated message consolidation to properly update senderPeerID
- Restored NIP-17 timestamp randomization (±15 minutes) for privacy

---------

Co-authored-by: jack <jackjackbits@users.noreply.github.com>
Co-authored-by: callebtc <93376500+callebtc@users.noreply.github.com>

bitchat/Nostr/NostrProtocol.swift

@@ -59,10 +59,11 @@ struct NostrProtocol {
     }
     
     /// Decrypt a received NIP-17 message
+    /// Returns the content, sender pubkey, and the actual message timestamp (not the randomized gift wrap timestamp)
     static func decryptPrivateMessage(
         giftWrap: NostrEvent,
         recipientIdentity: NostrIdentity
-    ) throws -> (content: String, senderPubkey: String) {
+    ) throws -> (content: String, senderPubkey: String, timestamp: Int) {
         
         // Starting decryption
         
@@ -94,7 +95,7 @@ struct NostrProtocol {
             throw error
         }
         
-        return (content: rumor.content, senderPubkey: rumor.pubkey)
+        return (content: rumor.content, senderPubkey: rumor.pubkey, timestamp: rumor.created_at)
     }
     
     // MARK: - Private Methods
@@ -438,8 +439,9 @@ struct NostrProtocol {
     
     private static func randomizedTimestamp() -> Date {
         // Add random offset to current time for privacy
-        // TEMPORARY: Reduced range to debug timestamp issue
-        let offset = TimeInterval.random(in: -60...60) // +/- 1 minute (was +/- 15 minutes)
+        // This prevents timing correlation attacks while the actual message timestamp
+        // is preserved in the encrypted rumor
+        let offset = TimeInterval.random(in: -900...900) // +/- 15 minutes
         let now = Date()
         let randomized = now.addingTimeInterval(offset)