Cool-light theme, Google event colors, photo frame contain+lower-right clock

- Main app swapped from warm cream/sage to cool slate light theme with
  blue accent; dark-* tokens and text-white/gray overrides remapped in
  tailwind.config.js and index.css
- Calendar events now render in Google's 11-color palette (Tomato through
  Graphite), deterministically hashed from the event summary so the same
  event always gets the same color
- PhotoFrame uses object-contain (whole photo shown, letterboxed) instead
  of object-cover; clock + date moved to lower-right, same white color,
  text-shadow for readability over any photo
- EMAIL_UPLOAD.md / PHOTO_FRAME.md / iCloud sync script and systemd timer
  remain unchanged

tailwind.config.js

@@ -7,44 +7,44 @@ module.exports = {
   theme: {
     extend: {
       colors: {
-        // Skylight-style warm light theme.
+        // Cool light theme (slate-based neutrals + blue accent).
         // Token names kept as "dark.*" so existing components don't need class changes.
         dark: {
-          primary: '#faf6f0',      // page bg - warm cream
+          primary: '#f1f5f9',       // page bg - slate-100
           secondary: '#ffffff',     // card bg - white
-          tertiary: '#f5ede1',      // subtle panels / compact rows
+          tertiary: '#e2e8f0',      // subtle panels - slate-200
           elevated: '#ffffff',      // elevated cards
-          hover: '#ede2cf',         // hover states
-          border: '#ebe0cc',        // soft warm borders
-          'border-light': '#d9cab0',
+          hover: '#e2e8f0',
+          border: '#e2e8f0',        // cool soft border
+          'border-light': '#cbd5e1',
         },
-        // Sage accent (Skylight uses muted greens/peach, not blue)
+        // Blue accent
         accent: {
-          DEFAULT: '#7fa894',       // sage
-          light: '#a0c2b1',
-          dark: '#5e8a76',
+          DEFAULT: '#3b82f6',       // blue-500
+          light: '#60a5fa',
+          dark: '#2563eb',
         },
-        // Warm ink text scale
+        // Cool slate ink text scale
         ink: {
-          DEFAULT: '#3a322a',       // primary dark text
-          muted: '#6b5f51',
-          subtle: '#8a7d6e',
-          faint: '#b0a494',
+          DEFAULT: '#0f172a',       // slate-900
+          muted: '#475569',         // slate-600
+          subtle: '#64748b',        // slate-500
+          faint: '#94a3b8',         // slate-400
         },
         status: {
-          success: '#4a9d7a',       // muted green
-          warning: '#d99a4a',       // warm amber
-          error: '#c75b5b',         // muted brick
+          success: '#16a34a',       // green-600
+          warning: '#d97706',       // amber-600
+          error: '#dc2626',         // red-600
         },
         // Legacy imperial tokens retained so old references don't break
         imperial: {
-          black: '#faf6f0',
-          dark: '#f5ede1',
-          medium: '#ebe0cc',
-          light: '#d9cab0',
-          red: '#c75b5b',
-          'red-dark': '#a84545',
-          'red-light': '#d97777',
+          black: '#f1f5f9',
+          dark: '#e2e8f0',
+          medium: '#cbd5e1',
+          light: '#94a3b8',
+          red: '#dc2626',
+          'red-dark': '#b91c1c',
+          'red-light': '#ef4444',
         },
       },
       fontFamily: {