Update insulation brand pages (Armaflex, Aeroflex, Maxflex)

- Added 3 new brand pages: armflex.astro, aeroflex.astro, maxflex.astro
- Updated hero images with product photos from 3t-insulation.com
- Enhanced content with product specifications and benefits
- Added standard certifications (FM Approved, UL 94, GREENGUARD)
- Added product gallery sections
- Shortened menu names to brand only (Armaflex, Aeroflex, Maxflex)
- Removed old ฉนวนหุ้มท่อ.astro page
- Updated Header and BaseLayout navigation
- Downloaded product images for all 3 brands

public/images/products-cropped/ppr-pipe.svg

@@ -0,0 +1,14 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="400" height="400" viewBox="0 0 400 400">
+  <defs>
+    <linearGradient id="bg" x1="0%" y1="0%" x2="100%" y2="100%">
+      <stop offset="0%" style="stop-color:#2d6a4f"/>
+      <stop offset="100%" style="stop-color:#1b4332"/>
+    </linearGradient>
+  </defs>
+  <rect width="400" height="400" fill="url(#bg)"/>
+  <circle cx="200" cy="180" r="60" fill="none" stroke="white" stroke-width="8"/>
+  <line x1="200" y1="120" x2="200" y2="240" stroke="white" stroke-width="12" stroke-linecap="round"/>
+  <line x1="140" y1="180" x2="260" y2="180" stroke="white" stroke-width="8"/>
+  <text x="200" y="300" text-anchor="middle" fill="white" font-family="sans-serif" font-size="24" font-weight="600">ท่อ PPR</text>
+  <text x="200" y="335" text-anchor="middle" fill="#a7f3d0" font-family="sans-serif" font-size="16">Thai PPR Pipe</text>
+</svg>