Opravy střední priority - sjednocení cest, lazy loading, minifikace

- Sjednoceny všechny relativní cesty na absolutní (od kořene /web/)
- Přidáno loading="lazy" pro všechny obrázky pod foldem
- Vytvořeny minifikované verze:
  - web/js/min/shared.min.js (125 → 3 řádky)
  - web/css/min/shared.min.css
  - web/css/min/variables.min.css
- Přidány dev dependencies: cssnano, terser
- Vytvořen minify.js skript pro budoucí minifikaci

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

web/minify.js

@@ -0,0 +1,67 @@
+const fs = require('fs');
+const path = require('path');
+const { minify: minifyJs } = require('terser');
+
+// Minify JavaScript files
+const jsFiles = [
+  'js/shared.js'
+];
+
+// Minify CSS files (simple approach - remove whitespace and comments)
+function minifyCss(content) {
+  return content
+    .replace(/\/\*[\s\S]*?\*\//g, '')  // Remove multi-line comments
+    .replace(/\/\*.*\*\//g, '')        // Remove single-line comments
+    .replace(/\s+/g, ' ')               // Collapse whitespace
+    .replace(/\s*([{}:;,>])\s*/g, '$1') // Remove spaces around brackets
+    .replace(/\s*\n\s*/g, '\n')        // Remove empty lines
+    .replace(/\n/g, '')                 // Remove all newlines
+    .trim();
+}
+
+async function minifyAll() {
+  // Minify JS files
+  for (const file of jsFiles) {
+    try {
+      const content = fs.readFileSync(file, 'utf8');
+      const result = await minifyJs(content, {
+        compress: {
+          drop_console: false,
+          keep_fnames: false,
+          passes: 2
+        },
+        mangle: true,
+        format: {
+          beautify: false,
+          comments: false
+        }
+      });
+      
+      const outputPath = file.replace('.js', '.min.js');
+      fs.writeFileSync(outputPath, result.code);
+      console.log(`Minified: ${file} -> ${outputPath}`);
+    } catch (error) {
+      console.error(`Error minifying ${file}:`, error);
+    }
+  }
+
+  // Minify CSS files
+  const cssFiles = [
+    'css/shared.css',
+    'css/variables.css'
+  ];
+
+  for (const file of cssFiles) {
+    try {
+      const content = fs.readFileSync(file, 'utf8');
+      const minified = minifyCss(content);
+      const outputPath = file.replace('.css', '.min.css');
+      fs.writeFileSync(outputPath, minified);
+      console.log(`Minified: ${file} -> ${outputPath}`);
+    } catch (error) {
+      console.error(`Error minifying ${file}:`, error);
+    }
+  }
+}
+
+minifyAll().catch(console.error);