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

dealplustech-astro/tsconfig.json

@@ -0,0 +1,5 @@
+{
+  "extends": "astro/tsconfigs/strict",
+  "include": [".astro/types.d.ts", "**/*"],
+  "exclude": ["dist"]
+}