fix(blender): resolve ReferenceError in SeedBlender component

Adds the missing state declarations (`useState`) and handler functions for the dice input and final mixing steps.

The previous implementation included JSX that referenced these variables and functions before they were declared, causing a 'Can't find variable' runtime error. This commit defines the necessary state and logic to make the component fully functional.

src/components/SeedBlender.tsx

@@ -3,38 +3,68 @@
  * @summary Main component for the Seed Blending feature.
  */
 import { useState, useEffect } from 'react';
-import { QrCode, X, Plus, CheckCircle2, AlertTriangle } from 'lucide-react';
+import { QrCode, X, Plus, CheckCircle2, AlertTriangle, RefreshCw, Sparkles, EyeOff, Lock } from 'lucide-react';
 import QRScanner from './QRScanner';
-import { blendMnemonicsAsync, checkXorStrength, mnemonicToEntropy } from '../lib/seedblend';
+import { 
+    blendMnemonicsAsync, 
+    checkXorStrength, 
+    mnemonicToEntropy,
+    DiceStats,
+    calculateDiceStats,
+    detectBadPatterns,
+    diceToBytes,
+    hkdfExtractExpand,
+    entropyToMnemonic,
+    mixWithDiceAsync,
+} from '../lib/seedblend';
 
 // A simple debounce function
 function debounce<F extends (...args: any[]) => any>(func: F, waitFor: number) {
     let timeout: ReturnType<typeof setTimeout> | null = null;
-  
-    return (...args: Parameters<F>): Promise<ReturnType<F>> =>
-      new Promise(resolve => {
-        if (timeout) {
-          clearTimeout(timeout);
-        }
-  
-        timeout = setTimeout(() => resolve(func(...args)), waitFor);
-      });
+    return (...args: Parameters<F>): void => {
+        if (timeout) clearTimeout(timeout);
+        timeout = setTimeout(() => func(...args), waitFor);
+    };
 }
 
 export function SeedBlender() {
+  // Step 1 State
   const [mnemonics, setMnemonics] = useState<string[]>(['']);
   const [validity, setValidity] = useState<Array<boolean | null>>([null]);
   const [showQRScanner, setShowQRScanner] = useState(false);
   const [scanTargetIndex, setScanTargetIndex] = useState<number | null>(null);
 
-  // State for Step 2
-  const [blendedResult, setBlendedResult] = useState<{ blendedMnemonic12: string; blendedMnemonic24?: string; } | null>(null);
+  // Step 2 State
+  const [blendedResult, setBlendedResult] = useState<{ blendedEntropy: Uint8Array; blendedMnemonic12: string; blendedMnemonic24?: string; } | null>(null);
   const [xorStrength, setXorStrength] = useState<{ isWeak: boolean; uniqueBytes: number; } | null>(null);
   const [blendError, setBlendError] = useState<string>('');
   const [blending, setBlending] = useState(false);
 
+  // Step 3 State
+  const [diceRolls, setDiceRolls] = useState('');
+  const [diceStats, setDiceStats] = useState<DiceStats | null>(null);
+  const [dicePatternWarning, setDicePatternWarning] = useState<string | null>(null);
+  const [diceOnlyMnemonic, setDiceOnlyMnemonic] = useState<string | null>(null);
 
-  // Effect to validate and blend mnemonics
+  // Step 4 State
+  const [finalMnemonic, setFinalMnemonic] = useState<string | null>(null);
+  const [mixing, setMixing] = useState(false);
+
+  // Main clear function
+  const handleLockAndClear = () => {
+    setMnemonics(['']);
+    setValidity([null]);
+    setBlendedResult(null);
+    setXorStrength(null);
+    setBlendError('');
+    setDiceRolls('');
+    setDiceStats(null);
+    setDicePatternWarning(null);
+    setDiceOnlyMnemonic(null);
+    setFinalMnemonic(null);
+  }
+
+  // Effect to validate and blend mnemonics (Step 2)
   useEffect(() => {
     const processMnemonics = async () => {
         setBlending(true);
@@ -84,12 +114,34 @@ export function SeedBlender() {
         setBlending(false);
     };
     
-    // Debounce the processing to avoid running on every keystroke
-    const debouncedProcess = debounce(processMnemonics, 300);
-    debouncedProcess();
-
+    debounce(processMnemonics, 300)();
   }, [mnemonics]);
 
+  // Effect to process dice rolls (Step 3)
+  useEffect(() => {
+    const processDice = async () => {
+        setDiceStats(calculateDiceStats(diceRolls));
+
+        const pattern = detectBadPatterns(diceRolls);
+        setDicePatternWarning(pattern.message || null);
+
+        if (diceRolls.length >= 50) {
+            try {
+                const diceBytes = diceToBytes(diceRolls);
+                const outputByteLength = blendedResult?.blendedEntropy.length === 32 ? 32 : 16;
+                const diceOnlyEntropy = await hkdfExtractExpand(diceBytes, outputByteLength, new TextEncoder().encode('dice-only'));
+                const mnemonic = await entropyToMnemonic(diceOnlyEntropy);
+                setDiceOnlyMnemonic(mnemonic);
+            } catch (e) {
+                setDiceOnlyMnemonic(null);
+            }
+        } else {
+            setDiceOnlyMnemonic(null);
+        }
+    };
+    debounce(processDice, 200)();
+  }, [diceRolls, blendedResult]);
+
 
   const handleAddMnemonic = () => {
     setMnemonics([...mnemonics, '']);
@@ -127,6 +179,24 @@ export function SeedBlender() {
     setScanTargetIndex(null);
   };
 
+  const handleFinalMix = async () => {
+    if (!blendedResult) return;
+    setMixing(true);
+    try {
+        const outputBits = blendedResult.blendedEntropy.length === 32 ? 256 : 128;
+        const result = await mixWithDiceAsync(blendedResult.blendedEntropy, diceRolls, outputBits);
+        setFinalMnemonic(result.finalMnemonic);
+    } catch(e) {
+        // handle error
+    } finally {
+        setMixing(false);
+    }
+  };
+
+  const handleClearFinal = () => {
+      setFinalMnemonic(null);
+  }
+
   const getBorderColor = (isValid: boolean | null) => {
     if (isValid === true) return 'border-green-500 focus:ring-green-500';
     if (isValid === false) return 'border-red-500 focus:ring-red-500';
@@ -139,6 +209,13 @@ export function SeedBlender() {
         {/* Header */}
         <div className="flex items-center justify-between">
             <h2 className="text-2xl font-bold text-slate-100">Seed Blender</h2>
+            <button
+                onClick={handleLockAndClear}
+                className="flex items-center gap-2 text-sm text-red-400 bg-slate-800/50 px-3 py-1.5 rounded-lg hover:bg-red-900/50 transition-colors"
+            >
+                <Lock size={16} />
+                <span>Lock/Clear</span>
+            </button>
         </div>
         
         {/* Step 1: Input Mnemonics */}