feat: enhance shortcuts modal and complete logos-to-icons rename

This commit includes graphical keyboard icons integration, modal styling
improvements, and comprehensive "Logos" to "Icons" terminology update.

Changes:
- Add graphical keyboard icons using Iconify MDI (Tab, Ctrl, Cmd, Esc, etc.)
- Implement color scheme: black title, green subtitle/headers, blue kbd elements
- Add visual boxes with borders and shadows for section grouping
- Change modal from 3-column to 2-column grid layout (900px width)
- Fix critical bug: all 5 sections now render (was only showing 2)

Rename "Logos" to "Icons" across entire codebase:
- Go models: ToggleLogos → ToggleIcons, ShowLogos → ShowIcons
- Routes: /toggle/logos → /toggle/icons
- Templates: desktop-logo-toggle → desktop-icon-toggle, #logoToggle → #iconToggle
- JavaScript: logoToggles → iconToggles, sync logic updated
- CSS: .show-logos → .show-icons
- UI JSON: toggleLogos → toggleIcons
- Comments and labels updated

Technical details:
- Rebuilt Go binary to fix template rendering error
- Fixed JSON struct tag: json:"toggleLogos" → json:"toggleIcons"
- Updated kbd element styling for icon alignment (inline-flex)
- Added margin-bottom to subtitle (0.5rem)
- Grid now 2 columns for better 5-section layout

All 5 sections now render correctly:
1. Zoom Control
2. View Controls
3. Navigation
4. Actions
5. Browser Defaults

static/css/print.css

@@ -45,7 +45,7 @@
     }
 
     /* ===================================
-       SHOW ALL ICONS, LOGOS, AND BADGES - Print Default
+       SHOW ALL ICONS, ICONS, AND BADGES - Print Default
        =================================== */
 
     /* Section title icons - smaller for print */
@@ -56,7 +56,7 @@
         margin-right: 4px !important;
     }
 
-    /* Company/Project/Course logos - compact for print */
+    /* Company/Project/Course icons - compact for print */
     .company-logo,
     .project-icon,
     .course-icon,
@@ -304,7 +304,7 @@
        EXPERIENCE - REDUCED SPACING (60px → 26px)
        =================================== */
     .experience-item {
-        display: flex !important; /* Show logos side-by-side with content */
+        display: flex !important; /* Show icons side-by-side with content */
         gap: 12px !important;
         margin-bottom: 4mm !important; /* ~15px, down from 40px */
         padding-bottom: 3mm !important; /* ~11px, down from 32px */
@@ -365,7 +365,7 @@
     .project-item,
     .course-item,
     .award-item {
-        display: flex !important; /* Show logos side-by-side with content */
+        display: flex !important; /* Show icons side-by-side with content */
         gap: 12px !important;
         margin-bottom: 4mm !important;
         padding-bottom: 3mm !important;