🧪 [testing improvement] Add validation for favicon and manifest tags

[xRahul]

🎯 What: The testing gap regarding the missing validation for favicon and manifest <link> tags in index.html has been addressed.
📊 Coverage: Playwright tests now verify the expected href paths for the manifest, apple-touch-icon, icon tags (16x16, 32x32, 96x96, 128x128, 192x192), mask-icon, and shortcut icon in index.html ensuring correct references to the /assets/favicons/ path and /manifest.json.
✨ Result: Test coverage significantly improves the website's SEO regression testing confidence, preventing issues related to missing or broken PWA/favicon asset references.

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PR created automatically by Jules for task 17244484197609301162 started by @xRahul

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