feat: smooth analog zoom with solid blue hover

UX improvements for more responsive, fluid zoom experience:

1. Smooth analog response:
   - Removed 50ms debounce - applies zoom immediately
   - Changed step from 5 to 1 for ultra-smooth increments
   - Updated transition: 0.08s linear (was 0.3s cubic-bezier)
   - Real-time transform updates for analog feel vs digital jumps

2. Solid blue hover (no gradient):
   - Changed from multi-color gradient to solid #3b82f6 blue
   - Maintains gray when not hovering
   - Clean, simple visual feedback matching reference design

3. Visual enhancement:
   - Keyboard shortcuts now use step 10 for faster adjustments
   - Instant response eliminates "digital" feeling
   - Smooth, continuous zoom matching analog controls

Technical changes:
- HTML: step="1" instead of step="5"
- CSS: solid color hover, 0.08s linear transition
- JS: removed debounce timeout, immediate applyZoom()

static/js/main.js

@@ -277,19 +277,13 @@
             applyZoom(zoomValue, false); // false = don't save (already loaded from storage)
         }
 
-        // Real-time slider updates with debouncing for performance
-        let zoomTimeout;
+        // Real-time slider updates - immediate, smooth analog experience
         slider.addEventListener('input', function(e) {
             const zoomValue = parseInt(e.target.value, 10);
 
-            // Update ARIA and display immediately (no debounce)
+            // Apply zoom and update display immediately for smooth analog feel
             updateZoomDisplay(zoomValue);
-
-            // Debounce the actual transform application (smoother on slower devices)
-            clearTimeout(zoomTimeout);
-            zoomTimeout = setTimeout(() => {
-                applyZoom(zoomValue, true);
-            }, 50); // 50ms debounce
+            applyZoom(zoomValue, true);
         });
 
         // Reset button
@@ -306,10 +300,10 @@
             if ((e.ctrlKey || e.metaKey) && !e.shiftKey) {
                 if (e.key === '=' || e.key === '+') {
                     e.preventDefault();
-                    incrementZoom(5);
+                    incrementZoom(10);
                 } else if (e.key === '-') {
                     e.preventDefault();
-                    incrementZoom(-5);
+                    incrementZoom(-10);
                 } else if (e.key === '0') {
                     e.preventDefault();
                     slider.value = 100;