Performance optimizations: formatter caching, view extraction, query limits (#1763)

* Performance optimizations: formatter caching, view extraction, query limits

- CoTMessage: Make ISO8601DateFormatter a static let instead of creating
  per toXML() call
- DiscoveryScanEngine: Add CustomStringConvertible to DiscoveryScanState,
  remove String(describing:) wrapper from log interpolations
- CarPlaySceneDelegate: Move favorite filter into #Predicate and add
  fetchLimit: 50 to avoid loading all nodes
- RateLimitedButton: Move objectWillChange.send() after cleanup check
  to avoid unnecessary view redraws after timer stops
- NodeDetail: Extract 600-line body into 6 @ViewBuilder section
  properties for granular SwiftUI diffing

* Fix persistent tip disappearing after 3 displays

Remove Tips.MaxDisplayCount(3) from ConnectionTip. The tip uses
PersistentTipStyle which has no dismiss button, so it should always
appear when connected. The max count caused TipKit to internally
invalidate the tip after 3 views, rendering it invisible.

* Potential fix for pull request finding

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* Use thread-safe CoT XML date formatting

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Co-authored-by: garthvh <1795163+garthvh@users.noreply.github.com>

* Fix review feedback in node admin and rate limiting

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Co-authored-by: garthvh <1795163+garthvh@users.noreply.github.com>

* Polish node administration guard logic

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---------

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: garthvh <1795163+garthvh@users.noreply.github.com>

Author: 3 people

Meshtastic/CarPlay/CarPlaySceneDelegate.swift

@@ -182,11 +182,13 @@ class CarPlaySceneDelegate: UIResponder, CPTemplateApplicationSceneDelegate, CPI
 
 	private func fetchFavoriteContactItems() -> [CPMessageListItem] {
 		do {
-			let descriptor = FetchDescriptor<NodeInfoEntity>(
+			let activeNum = Int64(AccessoryManager.shared.activeDeviceNum ?? 0)
+			var descriptor = FetchDescriptor<NodeInfoEntity>(
+				predicate: #Predicate<NodeInfoEntity> { $0.favorite == true && $0.num != activeNum },
 				sortBy: [SortDescriptor(\.lastHeard, order: .reverse)]
 			)
-			let activeNum = AccessoryManager.shared.activeDeviceNum ?? 0
-			let nodes = try context.fetch(descriptor).filter { $0.favorite && $0.num != activeNum }
+			descriptor.fetchLimit = 50
+			let nodes = try context.fetch(descriptor)
 			let nodeNums = nodes.compactMap { $0.user != nil ? $0.num : nil as Int64? }
 			let unreadCounts = fetchUnreadCountsForDMs(nodeNums: nodeNums)
 			let now = Date()

Meshtastic/Helpers/TAK/CoTMessage.swift

@@ -282,16 +282,17 @@ struct CoTMessage: Identifiable, Sendable {
 	// MARK: - XML Generation
 
 	/// Generate CoT XML string for transmission to TAK clients
+	private static let xmlDateFormatStyle = Date.ISO8601FormatStyle(includingFractionalSeconds: true, timeZone: TimeZone(secondsFromGMT: 0)!)
+
 	func toXML() -> String {
-		let dateFormatter = ISO8601DateFormatter()
-		dateFormatter.formatOptions = [.withInternetDateTime, .withFractionalSeconds]
+		let dateFormatter = Self.xmlDateFormatStyle
 
 		var cot = "<?xml version='1.0' encoding='UTF-8' standalone='yes'?>"
 		cot += "<event version='2.0' uid='\(uid.xmlEscaped)' "
 		cot += "type='\(type)' "
-		cot += "time='\(dateFormatter.string(from: time))' "
-		cot += "start='\(dateFormatter.string(from: start))' "
-		cot += "stale='\(dateFormatter.string(from: stale))' "
+		cot += "time='\(time.formatted(dateFormatter))' "
+		cot += "start='\(start.formatted(dateFormatter))' "
+		cot += "stale='\(stale.formatted(dateFormatter))' "
 		cot += "how='\(how)'>"
 		cot += "<point lat='\(latitude)' lon='\(longitude)' "
 		cot += "hae='\(hae)' ce='\(ce)' le='\(le)'/>"

Meshtastic/Services/DiscoveryScanEngine.swift

@@ -16,7 +16,7 @@ import SwiftUI
 
 // MARK: - Scan State
 
-enum DiscoveryScanState: Equatable {
+enum DiscoveryScanState: Equatable, CustomStringConvertible {
 	case idle
 	case shifting
 	case reconnecting
@@ -25,6 +25,19 @@ enum DiscoveryScanState: Equatable {
 	case complete
 	case paused
 	case restoring
+
+	var description: String {
+		switch self {
+		case .idle: "idle"
+		case .shifting: "shifting"
+		case .reconnecting: "reconnecting"
+		case .dwell: "dwell"
+		case .analysis: "analysis"
+		case .complete: "complete"
+		case .paused: "paused"
+		case .restoring: "restoring"
+		}
+	}
 }
 
 // MARK: - DiscoveryScanEngine
@@ -91,7 +104,7 @@ final class DiscoveryScanEngine {
 
 	func startScan() async {
 		guard currentState == .idle else {
-			Logger.discovery.warning("📡 [Discovery] Cannot start scan — not idle (state: \(String(describing: self.currentState)))")
+			Logger.discovery.warning("📡 [Discovery] Cannot start scan — not idle (state: \(self.currentState))")
 			return
 		}
 		guard !selectedPresets.isEmpty else {
@@ -688,7 +701,7 @@ extension DiscoveryScanEngine {
 	private func transitionTo(_ newState: DiscoveryScanState) {
 		let oldState = currentState
 		currentState = newState
-		Logger.discovery.info("📡 [Discovery] State: \(String(describing: oldState)) → \(String(describing: newState))")
+		Logger.discovery.info("📡 [Discovery] State: \(oldState) → \(newState)")
 	}
 
 	private func cleanupAndIdle() {

Meshtastic/Tips/BluetoothTips.swift

@@ -23,6 +23,5 @@ struct ConnectionTip: Tip {
 	}
 	var options: [TipOption] {
 		Tips.IgnoresDisplayFrequency(true)
-		Tips.MaxDisplayCount(3)
 	}
 }

Meshtastic/Views/Helpers/RateLimitedButton.swift

@@ -108,16 +108,17 @@ class RateLimitStorage: ObservableObject {
 		// Create the timer
 		self.timer = Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { [weak self] _ in
 			guard let self = self else { return }
-			self.objectWillChange.send()
 
 			// Determine if we can clean up the dictionary and stop the timer.
 			let maxExpiration = self.rateLimits.values.map { $0.rateLimitExpires }.max() ?? .distantPast
 			if maxExpiration.timeIntervalSinceNow < 0 {
-				// All rateLimits are in the past.  Stop and clean up
+				// All rateLimits are in the past. Stop and clean up
 				self.timer?.invalidate()
 				self.timer = nil
 				self.rateLimits.removeAll()
+				return
 			}
+			self.objectWillChange.send()
 		}
 	}
 }