fix: decibel logarithmic loudness metering and Apple Intelligence sapphire blue dynamic HUD redesign

src/AudioRecorder.swift

@@ -151,14 +151,16 @@ public final class AudioRecorder: NSObject, AVCaptureAudioDataOutputSampleBuffer
                 // Stream live audio chunk to WebSocket immediately
                 onAudioChunkAvailable?(data)
                 
-                // Calculate RMS level for HUD
+                // Calculate decibel loudness for perceptual, high-responsiveness audio meter
                 var sumSquare: Float = 0
                 for i in 0..<frameLen {
                     let sample = Float(int16Ptr[i]) / 32768.0
                     sumSquare += sample * sample
                 }
                 let rms = sqrt(sumSquare / Float(frameLen))
-                let normalizedLevel = min(max(rms * 4.5, 0.0), 1.0)
+                // Convert to decibels (-50 dB noise floor to -12 dB peak speech)
+                let db = 20.0 * log10(max(rms, 0.00001))
+                let normalizedLevel = min(max((db + 48.0) / 36.0, 0.0), 1.0)
                 
                 DispatchQueue.main.async { [weak self] in
                     self?.onAudioLevelUpdate?(normalizedLevel)

src/HUDOverlay.swift

@@ -14,7 +14,7 @@ public final class HUDOverlayController {
     public static let shared = HUDOverlayController()
     
     private var window: NSPanel?
-    private var orbView: SolidSiriOrbView?
+    private var orbView: AppleIntelligenceOrbView?
     private var isVisible = false
     
     // Large transparent canvas so audio-reactive halo never clips
@@ -44,10 +44,10 @@ public final class HUDOverlayController {
         let container = NSView(frame: panel.contentView!.bounds)
         container.wantsLayer = true
         
-        // Minimal Solid Orb centered in canvas
-        let orbDiameter: CGFloat = 50
+        // Professional Apple Intelligence Orb centered in canvas
+        let orbDiameter: CGFloat = 54
         let orbOrigin = (canvasSize - orbDiameter) / 2.0
-        let orb = SolidSiriOrbView(frame: NSRect(x: orbOrigin, y: orbOrigin, width: orbDiameter, height: orbDiameter))
+        let orb = AppleIntelligenceOrbView(frame: NSRect(x: orbOrigin, y: orbOrigin, width: orbDiameter, height: orbDiameter))
         container.addSubview(orb)
         self.orbView = orb
         
@@ -59,9 +59,9 @@ public final class HUDOverlayController {
     private func reposition() {
         guard let window = self.window, let screen = NSScreen.main else { return }
         let screenRect = screen.visibleFrame
-        // Center horizontally, positioned comfortably higher above the dock
+        // Center horizontally, positioned comfortably higher above dock
         let x = screenRect.midX - (canvasSize / 2.0)
-        let y = screenRect.minY + 75
+        let y = screenRect.minY + 68
         window.setFrameOrigin(NSPoint(x: x, y: y))
     }
     
@@ -127,14 +127,15 @@ public final class HUDOverlayController {
     }
 }
 
-// MARK: - Minimal Solid-Color Orb with 100% Dynamic Audio-Driven Stroke & Bloom Halo
+// MARK: - Professional Apple Intelligence Orb View
 
-final class SolidSiriOrbView: NSView {
+final class AppleIntelligenceOrbView: NSView {
     private let glowLayer = CALayer()
-    private let solidCoreLayer = CALayer()
+    private let coreGradientLayer = CAGradientLayer()
     private let strokeBorderLayer = CALayer()
     
-    private let maxStrokeWidth: CGFloat = 8.0
+    private let minStrokeWidth: CGFloat = 2.0
+    private let maxStrokeWidth: CGFloat = 7.5
     
     override init(frame frameRect: NSRect) {
         super.init(frame: frameRect)
@@ -155,75 +156,85 @@ final class SolidSiriOrbView: NSView {
         let bounds = self.bounds
         let radius = bounds.width / 2.0
         
-        // 1. Dynamic Outer Atmospheric Glow (100% audio-driven; disappears completely in silence)
-        glowLayer.frame = bounds.insetBy(dx: -12, dy: -12)
-        glowLayer.cornerRadius = (bounds.width + 24) / 2.0
-        glowLayer.backgroundColor = NSColor.clear.cgColor
-        glowLayer.shadowColor = NSColor.white.cgColor
-        glowLayer.shadowRadius = 0
-        glowLayer.shadowOpacity = 0.0
+        // 1. Atmospheric Ambient Glow (Expands and blooms with decibel level)
+        glowLayer.frame = bounds.insetBy(dx: -10, dy: -10)
+        glowLayer.cornerRadius = (bounds.width + 20) / 2.0
+        glowLayer.backgroundColor = NSColor(red: 0.0, green: 0.70, blue: 1.0, alpha: 0.25).cgColor
+        glowLayer.shadowColor = NSColor(red: 0.0, green: 0.85, blue: 1.0, alpha: 0.85).cgColor
+        glowLayer.shadowRadius = 12
+        glowLayer.shadowOpacity = 0.45
         glowLayer.shadowOffset = .zero
-        glowLayer.opacity = 0.0
         layer.addSublayer(glowLayer)
         
-        // 2. Chic, Minimal Solid-Color Core (Apple Obsidian Graphite Disc)
-        solidCoreLayer.frame = bounds
-        solidCoreLayer.cornerRadius = radius
-        solidCoreLayer.backgroundColor = NSColor(red: 0.12, green: 0.12, blue: 0.14, alpha: 0.98).cgColor
-        layer.addSublayer(solidCoreLayer)
-        
-        // 3. Dynamic Voice-Reactive Stroke Ring (Disappears completely in silence)
+        // 2. Deep Sapphire/Midnight Blue Radial Core (Clean, minimal, luxury Apple design)
+        coreGradientLayer.frame = bounds
+        coreGradientLayer.cornerRadius = radius
+        coreGradientLayer.type = .radial
+        coreGradientLayer.colors = [
+            NSColor(red: 0.05, green: 0.55, blue: 0.95, alpha: 1.0).cgColor,  // Vibrant Cerulean Center
+            NSColor(red: 0.12, green: 0.18, blue: 0.55, alpha: 0.98).cgColor, // Deep Royal Blue
+            NSColor(red: 0.06, green: 0.08, blue: 0.22, alpha: 0.98).cgColor  // Midnight Obsidian Edge
+        ]
+        coreGradientLayer.startPoint = CGPoint(x: 0.40, y: 0.40)
+        coreGradientLayer.endPoint = CGPoint(x: 1.0, y: 1.0)
+        layer.addSublayer(coreGradientLayer)
+        
+        // 3. Audio-Reactive Neon Stroke (Widening & Brightening dynamically with voice)
         strokeBorderLayer.frame = bounds
         strokeBorderLayer.cornerRadius = radius
-        strokeBorderLayer.borderWidth = 0.0
-        strokeBorderLayer.borderColor = NSColor.white.cgColor
+        strokeBorderLayer.borderWidth = minStrokeWidth
+        strokeBorderLayer.borderColor = NSColor(red: 0.30, green: 0.90, blue: 1.0, alpha: 0.75).cgColor
         strokeBorderLayer.backgroundColor = NSColor.clear.cgColor
-        strokeBorderLayer.opacity = 0.0
         layer.addSublayer(strokeBorderLayer)
     }
     
     /// Updates audio response:
-    /// In silence (level <= 0.04): stroke and halo disappear completely.
-    /// When speaking: stroke widens powerfully (up to 8px) and halo blooms dynamically.
+    /// In silence (level ~ 0.0): crisp minimal 2px stroke, subtle soft glow.
+    /// When speaking: stroke powerfully thickens up to 7.5px, glow blooms to 42px, smooth gentle scale breathing.
     func updateAudioLevel(_ level: Float, isLagging: Bool) {
         CATransaction.begin()
         CATransaction.setDisableActions(true)
         
-        let rawClamped = CGFloat(min(max(level, 0.0), 1.0))
-        let silenceThreshold: CGFloat = 0.04
-        
-        if rawClamped <= silenceThreshold {
-            // Complete silence: Stroke and Halo completely vanish
-            strokeBorderLayer.borderWidth = 0.0
-            strokeBorderLayer.opacity = 0.0
-            glowLayer.shadowOpacity = 0.0
-            glowLayer.shadowRadius = 0.0
-            glowLayer.opacity = 0.0
-        } else {
-            // Active speech: scale dynamic intensity noticeably
-            let norm = (rawClamped - silenceThreshold) / (1.0 - silenceThreshold)
+        let clamped = CGFloat(min(max(level, 0.0), 1.0))
         
         if isLagging {
-                // Amber highlight for network degradation
-                let amber = NSColor(red: 1.0, green: 0.65, blue: 0.10, alpha: 0.95).cgColor
-                strokeBorderLayer.borderColor = amber
-                glowLayer.shadowColor = amber
+            // Amber warm warning for degraded internet
+            coreGradientLayer.colors = [
+                NSColor(red: 1.0, green: 0.75, blue: 0.15, alpha: 1.0).cgColor,
+                NSColor(red: 0.85, green: 0.40, blue: 0.05, alpha: 0.98).cgColor,
+                NSColor(red: 0.25, green: 0.10, blue: 0.02, alpha: 0.98).cgColor
+            ]
+            let amberStroke = NSColor(red: 1.0, green: 0.80, blue: 0.25, alpha: 0.7 + (0.3 * clamped)).cgColor
+            strokeBorderLayer.borderColor = amberStroke
+            glowLayer.shadowColor = NSColor.orange.cgColor
         } else {
-                // Crisp luminous white glow
-                strokeBorderLayer.borderColor = NSColor.white.cgColor
-                glowLayer.shadowColor = NSColor.white.cgColor
+            // Standard crisp Apple Intelligence sapphire palette
+            coreGradientLayer.colors = [
+                NSColor(red: 0.05, green: 0.55 + (0.40 * clamped), blue: 0.95 + (0.05 * clamped), alpha: 1.0).cgColor,
+                NSColor(red: 0.12, green: 0.18, blue: 0.55, alpha: 0.98).cgColor,
+                NSColor(red: 0.06, green: 0.08, blue: 0.22, alpha: 0.98).cgColor
+            ]
+            let neonStroke = NSColor(
+                red: 0.30 + (0.60 * clamped),
+                green: 0.90 + (0.10 * clamped),
+                blue: 1.0,
+                alpha: 0.65 + (0.35 * clamped)
+            ).cgColor
+            strokeBorderLayer.borderColor = neonStroke
+            glowLayer.shadowColor = NSColor(red: 0.0, green: 0.85, blue: 1.0, alpha: 0.90).cgColor
         }
         
-            // 1. Noticeably powerful stroke expansion (from 0 to 8px)
-            let dynamicWidth = norm * maxStrokeWidth
+        // 1. Dynamic Stroke Expansion: thickens from 2.0px to 7.5px noticeably
+        let dynamicWidth = minStrokeWidth + (clamped * (maxStrokeWidth - minStrokeWidth))
         strokeBorderLayer.borderWidth = dynamicWidth
-            strokeBorderLayer.opacity = Float(0.40 + (0.60 * norm))
         
-            // 2. Dynamic bloom halo (expands up to 45px radius)
-            glowLayer.shadowRadius = 6.0 + (norm * 38.0)
-            glowLayer.shadowOpacity = Float(0.35 + (0.65 * norm))
-            glowLayer.opacity = Float(norm)
-        }
+        // 2. Dynamic Bloom Halo: blooms from 12px up to 42px
+        glowLayer.shadowRadius = 12.0 + (clamped * 30.0)
+        glowLayer.shadowOpacity = Float(0.45 + (0.50 * clamped))
+        
+        // 3. Subtle organic breathing scale (1.0 to 1.14x max, smooth and stable without shaking)
+        let subtleScale = 1.0 + (clamped * 0.14)
+        self.layer?.sublayerTransform = CATransform3DMakeScale(subtleScale, subtleScale, 1.0)
         
         CATransaction.commit()
     }
@@ -233,12 +244,10 @@ final class SolidSiriOrbView: NSView {
         CATransaction.setDisableActions(false)
         CATransaction.setAnimationDuration(0.20)
         strokeBorderLayer.borderWidth = 4.0
-        strokeBorderLayer.opacity = 1.0
         strokeBorderLayer.borderColor = NSColor.orange.cgColor
         glowLayer.shadowColor = NSColor.orange.cgColor
         glowLayer.shadowRadius = 24
         glowLayer.shadowOpacity = 0.9
-        glowLayer.opacity = 1.0
         CATransaction.commit()
     }
     
@@ -246,12 +255,9 @@ final class SolidSiriOrbView: NSView {
         CATransaction.begin()
         CATransaction.setDisableActions(true)
         strokeBorderLayer.borderWidth = 3.0
-        strokeBorderLayer.opacity = 0.8
-        strokeBorderLayer.borderColor = NSColor.white.cgColor
-        glowLayer.shadowColor = NSColor.white.cgColor
-        glowLayer.shadowRadius = 16
-        glowLayer.shadowOpacity = 0.7
-        glowLayer.opacity = 0.8
+        strokeBorderLayer.borderColor = NSColor.cyan.cgColor
+        glowLayer.shadowRadius = 18
+        glowLayer.shadowOpacity = 0.8
         CATransaction.commit()
     }
     
@@ -261,12 +267,10 @@ final class SolidSiriOrbView: NSView {
         CATransaction.setAnimationDuration(0.18)
         let green = NSColor(red: 0.15, green: 0.95, blue: 0.45, alpha: 1.0).cgColor
         strokeBorderLayer.borderWidth = 4.0
-        strokeBorderLayer.opacity = 1.0
         strokeBorderLayer.borderColor = green
         glowLayer.shadowColor = green
-        glowLayer.shadowRadius = 22
-        glowLayer.shadowOpacity = 0.9
-        glowLayer.opacity = 1.0
+        glowLayer.shadowRadius = 24
+        glowLayer.shadowOpacity = 0.95
         CATransaction.commit()
     }
     
@@ -276,23 +280,21 @@ final class SolidSiriOrbView: NSView {
         CATransaction.setAnimationDuration(0.18)
         let red = NSColor(red: 1.0, green: 0.20, blue: 0.20, alpha: 1.0).cgColor
         strokeBorderLayer.borderWidth = 4.0
-        strokeBorderLayer.opacity = 1.0
         strokeBorderLayer.borderColor = red
         glowLayer.shadowColor = red
-        glowLayer.shadowRadius = 22
-        glowLayer.shadowOpacity = 0.9
-        glowLayer.opacity = 1.0
+        glowLayer.shadowRadius = 24
+        glowLayer.shadowOpacity = 0.95
         CATransaction.commit()
     }
     
     func reset() {
         CATransaction.begin()
         CATransaction.setDisableActions(true)
-        strokeBorderLayer.borderWidth = 0.0
-        strokeBorderLayer.opacity = 0.0
-        glowLayer.shadowRadius = 0.0
-        glowLayer.shadowOpacity = 0.0
-        glowLayer.opacity = 0.0
+        self.layer?.sublayerTransform = CATransform3DIdentity
+        strokeBorderLayer.borderWidth = minStrokeWidth
+        strokeBorderLayer.borderColor = NSColor(red: 0.30, green: 0.90, blue: 1.0, alpha: 0.75).cgColor
+        glowLayer.shadowRadius = 12
+        glowLayer.shadowOpacity = 0.45
         CATransaction.commit()
     }
 }