feat: Fix product tables and responsive fonts

- Add product detail page ([slug].astro) with table rendering
- Display productTables from site-config.ts on product pages
- Add responsive font scaling for large screens (1280px+)
- Base font scales from 16px to 24px on 4K displays
- All text elements use responsive sizing (md/lg/xl breakpoints)
- Tables styled with green headers and alternating rows
- Add comprehensive documentation (FIXES_SUMMARY.md)

Fixes:
- Product specification tables now visible on product pages
- Font too small on large screens - now responsive

hvac_product_tables.json

@@ -0,0 +1,84 @@
+{
+  "product": "HVAC Products",
+  "tables": [
+    {
+      "productName": "DURGO AAVs (Air Admittance Valve)",
+      "tableName": "AAV Series Specifications",
+      "headers": ["Model", "Connection Type", "Flow Capacity (l/s)", "Colour", "EN 12380 Standard Compliance"],
+      "rows": [
+        ["AAV-75", "Straight End", "37.0", "Black/White", "Type A1"],
+        ["AAV-89", "Straight End", "47.5", "Black/White", "Type A1"],
+        ["AAV-110", "Straight End", "44.2", "Black/White", "Type B1"],
+        ["AAV-114", "Straight End", "72.2", "Black/White", "Type B1"],
+        ["AAV-140", "Straight End", "103.4", "Black/White", "Type B1"],
+        ["AAV-160", "Straight End", "103.7", "Black/White", "Type B1"]
+      ]
+    },
+    {
+      "productName": "DURGO AAVs (Air Admittance Valve)",
+      "tableName": "Product Dimensions Specification",
+      "headers": ["Product Code", "H (mm)", "D (mm)", "Dia. (mm)"],
+      "rows": [
+        ["AAV-NPT1", "67", "54", "Thread 1\""],
+        ["AAV-40", "77", "70", "40"],
+        ["AAV-50", "95", "84", "50"],
+        ["AAV-60", "95", "84", "60"],
+        ["AAV-75", "106", "119", "75"],
+        ["AAV-89", "119", "139", "89"],
+        ["AAV-110", "124", "139", "110"],
+        ["AAV-114", "113", "172", "114"],
+        ["AAV-140", "149", "211", "140"],
+        ["AAV-160", "152", "211", "160"]
+      ]
+    },
+    {
+      "productName": "DURGO AAVs (Air Admittance Valve)",
+      "tableName": "Selection Criteria - PVC Pipes (JIS Standard) - Main Stack",
+      "headers": ["Pipe Size", "DURGO Model"],
+      "rows": [
+        ["3\"", "AAV-89"],
+        ["4\"", "AAV-114"],
+        ["6\" or larger", "AAV-140"]
+      ]
+    },
+    {
+      "productName": "DURGO AAVs (Air Admittance Valve)",
+      "tableName": "Selection Criteria - PVC Pipes (JIS Standard) - Branch Pipe",
+      "headers": ["Pipe Size", "DURGO Model"],
+      "rows": [
+        ["2\"", "AAV-NPT1"],
+        ["2-1/2\"", "AAV-50"],
+        ["3\"", "AAV-50"],
+        ["4\"", "AAV-60"],
+        ["6\"", "AAV-89"]
+      ]
+    },
+    {
+      "productName": "DURGO AAVs (Air Admittance Valve)",
+      "tableName": "Selection Criteria - XYLENT, PE, PP Pipes (EN Standard) - Main Stack",
+      "headers": ["Pipe Size", "DURGO Model"],
+      "rows": [
+        ["3\"", "AAV-75"],
+        ["4\"", "AAV-110"],
+        ["6\" or larger", "AAV-160"]
+      ]
+    },
+    {
+      "productName": "DURGO AAVs (Air Admittance Valve)",
+      "tableName": "Selection Criteria - XYLENT, PE, PP Pipes (EN Standard) - Branch Pipe",
+      "headers": ["Pipe Size", "DURGO Model"],
+      "rows": [
+        ["2\"", "AAV-40"],
+        ["3\"", "AAV-50"],
+        ["4\"", "AAV-50"],
+        ["6\"", "AAV-75"]
+      ]
+    }
+  ],
+  "notes": {
+    "airGrilles": "No specification tables found on /grilles/ page - only product descriptions and images",
+    "ballJetDiffuser": "No specification tables found on /หัวจ่ายแอร์-ball-jet/ page - only product descriptions and images",
+    "thermobreak": "No specification tables found on /เทอร์โมเบรค-thermobreak/ page - only product descriptions and images",
+    "durgoAirValve": "Found specification tables embedded in images on /durgo-avvs/ page - extracted 6 tables total"
+  }
+}