Add mobile app badges and tiktok to landing page

[nabramow]

Describe briefly what this PR is doing and why.

• Adds the apple and google play badges to the landing page above the folder and in footer
• Adds tiktok to the social media links in the footer since we have some tiktok content now

Closes #8621

Testing

Explain how you tested this PR and give clear steps so the reviewer can replicate.

• Make sure the links work on your phone

Web frontend checklist

• There are no console warnings when running the app
• Added tests where relevant
• Clicked around my changes running locally and it works
• Checked Desktop, Mobile and Tablet screen sizes

For maintainers

• Maintainers can push commits to my branch
• Maintainers can merge this PR for me

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Project	Deployment	Actions	Updated (UTC)
couchers	Ready	Preview	May 16, 2026 4:29pm

[jesseallhands]

Landing page app store buttons look good! The "learn more" link above the buttons on mobile web looks a bit small compared to the buttons, but that's probably unrelated to this PR.

The spacing of the app store buttons in the footer should be updated so the outer edges align with the volunteer button outer edge:

[github-actions]

📝 Release Notes

This PR should be included in the release notes.

Suggested release note:

Added App Store and Google Play download buttons to the landing page and footer so it’s easier to find and install the Couchers mobile app

🤖 Bot Debug Information

Model: couchers.openai.gpt-5.4
Decision: include
Reasoning: This adds visible app store download badges to the landing page and footer, making it easier for users to discover and install the mobile app. The TikTok footer link is minor, but the app promotion is a noticeable user-facing improvement.