fix: resolve TypeScript type errors

Fixed several TypeScript issues:
- Changed 'formatter' to 'formatValue' in CircularKnob props
- Added explicit type annotations for formatValue functions
- Initialized animationFrameRef with undefined value
- Removed unused Waveform import from TrackControls

All type checks now pass.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

components/analysis/FrequencyAnalyzer.tsx

@@ -10,7 +10,7 @@ export interface FrequencyAnalyzerProps {
 
 export function FrequencyAnalyzer({ analyserNode, className }: FrequencyAnalyzerProps) {
   const canvasRef = React.useRef<HTMLCanvasElement>(null);
-  const animationFrameRef = React.useRef<number>();
+  const animationFrameRef = React.useRef<number | undefined>(undefined);
 
   React.useEffect(() => {
     if (!analyserNode || !canvasRef.current) return;

components/analysis/Spectrogram.tsx

@@ -10,7 +10,7 @@ export interface SpectrogramProps {
 
 export function Spectrogram({ analyserNode, className }: SpectrogramProps) {
   const canvasRef = React.useRef<HTMLCanvasElement>(null);
-  const animationFrameRef = React.useRef<number>();
+  const animationFrameRef = React.useRef<number | undefined>(undefined);
   const spectrogramDataRef = React.useRef<ImageData | null>(null);
 
   React.useEffect(() => {

components/controls/MasterControls.tsx

@@ -51,7 +51,7 @@ export function MasterControls({
         step={0.01}
         label="PAN"
         size={48}
-        formatter={(value) => {
+        formatValue={(value: number) => {
           if (Math.abs(value) < 0.01) return 'C';
           if (value < 0) return `${Math.abs(value * 100).toFixed(0)}L`;
           return `${(value * 100).toFixed(0)}R`;

components/tracks/TrackControls.tsx

@@ -1,7 +1,7 @@
 'use client';
 
 import * as React from 'react';
-import { Circle, Headphones, Waveform, MoreHorizontal } from 'lucide-react';
+import { Circle, Headphones, MoreHorizontal } from 'lucide-react';
 import { CircularKnob } from '@/components/ui/CircularKnob';
 import { TrackFader } from './TrackFader';
 import { cn } from '@/lib/utils/cn';
@@ -72,7 +72,7 @@ export function TrackControls({
           step={0.01}
           label="PAN"
           size={40}
-          formatter={(value) => {
+          formatValue={(value: number) => {
             if (Math.abs(value) < 0.01) return 'C';
             if (value < 0) return `${Math.abs(value * 100).toFixed(0)}L`;
             return `${(value * 100).toFixed(0)}R`;