refactor(ux): simplify jargon and improve feature discoverability

Addressed P3 design opportunities from critique:

1. Technical Jargon Simplification
   - "Optical Assist" → "Smart Scan" (clearer scanning intent)
   - "Protocol Detected" → "Text Found" (plain language)
   - "OCR Matching Key" → "Item ID or Code" (concrete terminology)
   - "Select identity from label matrix" → "Tap any text to use it"
   - Removed cryptic "Cycle" terminology, added countdown seconds

2. Feature Discoverability
   - Added helpful descriptions to Admin manager sections
   - Scanner status message now hints at zoom and tap features
   - Concrete examples in input placeholders

3. Help & Documentation
   - User Management: "Create accounts and control access"
   - Category Groups: "Organize items by type or location"
   - Sign Out: clearer procedure description

Build: passes with zero errors

frontend/components/Scanner.tsx

@@ -257,14 +257,14 @@ export default function Scanner({ onScanSuccess, onOCRMatch, paused }: ScannerPr
             </div>
             <div className="p-6 bg-slate-900/90 border-t border-slate-800 flex flex-col gap-4">
                <div className="flex flex-col items-center gap-1">
-                 <p className="text-sm font-black text-white italic text-center">Protocol Detected</p>
-                 <p className="text-xs text-slate-500 font-black text-center">Select identity from label matrix</p>
+                 <p className="text-sm font-black text-white italic text-center">Text Found</p>
+                 <p className="text-xs text-slate-500 font-black text-center">Tap any text to use it</p>
                </div>
-               <button 
+               <button
                  onClick={() => { setIsSelecting(false); setCapturedImage(null); setCountdown(4); }}
                  className="w-full py-4 bg-slate-800 hover:bg-slate-700 text-white rounded-2xl font-black text-xs transition-all active:scale-95 border border-slate-700"
                >
-                 Abort Cycle
+                 Cancel
                </button>
             </div>
           </div>
@@ -330,9 +330,9 @@ export default function Scanner({ onScanSuccess, onOCRMatch, paused }: ScannerPr
                   <>
                     <Search className={cn("text-slate-600 transition-colors group-hover:text-primary", !isStarted && "opacity-20")} size={18} />
                     <div className="flex flex-col">
-                        <span className="text-xs text-slate-500 font-black leading-none">Optical Assist</span>
+                        <span className="text-xs text-slate-500 font-black leading-none">Smart Scan</span>
                         <span className="text-xs font-black text-primary leading-tight tabular-nums">
-                            {countdown === 0 ? "Scanning" : `${countdown}s Cycle`}
+                            {countdown === 0 ? "Scanning" : `${countdown}s`}
                         </span>
                     </div>
                   </>
@@ -349,7 +349,7 @@ export default function Scanner({ onScanSuccess, onOCRMatch, paused }: ScannerPr
         <div className="w-full flex justify-center items-center gap-2">
           <div className="w-1 h-1 rounded-full bg-green-500 animate-pulse" />
           <p className="text-xs text-slate-600 font-black">
-            Optical Data Stream Active
+            Scanner active · Use zoom or tap scan
           </p>
         </div>
       </div>