Refactor SupportModal into core lib, add CAPTCHA & clean up repo pages

[jfrench9]

Summary

This PR consolidates the SupportModal component into the src/lib/core module, adds Cloudflare Turnstile CAPTCHA verification to the support submission flow, and performs minor cleanup on repository page components.

What changed

SupportModal relocation & enhancement

• Moved SupportModal from src/components/app/ to src/lib/core/ui-components/support/, integrating it into the shared core library for better reusability and organization.
• Updated layout-wrapper.tsx to import SupportModal from its new location.
• Significantly enhanced the SupportModal component with Cloudflare Turnstile CAPTCHA integration, adding client-side token generation before form submission.

CAPTCHA verification (Turnstile)

• Added a new src/lib/core/utils/turnstile-config.ts utility with Turnstile site key configuration and helper utilities.
• Added server-side CAPTCHA token verification in src/app/api/support/route.ts, validating the Turnstile token against Cloudflare's siteverify endpoint before processing support requests.

Repository page cleanup

• Removed unused code/imports from ActiveSubscriptions.tsx.
• Minor updates to BrowseRepositories.tsx (likely import or rendering adjustments).

Core library barrel exports

• Updated src/lib/core/index.ts and src/lib/core/ui-components/index.ts to export the new SupportModal and support-related modules.
• Added src/lib/core/ui-components/support/index.ts barrel file.

Key UI/UX Improvements

• Bot protection: Support form submissions are now protected by Cloudflare Turnstile CAPTCHA, reducing spam and abuse without degrading the user experience (Turnstile is non-intrusive compared to traditional CAPTCHAs).
• No visible UI regression — the SupportModal behaves the same from the user's perspective, with the addition of the invisible/managed Turnstile challenge widget.

Breaking Changes

• Import path change: Any code importing SupportModal from src/components/app/SupportModal will break. All imports must now reference src/lib/core/ui-components/support (or the core barrel export). This PR updates all known consumers.
• Environment variable requirement: The Turnstile secret key must be configured server-side for the support API route to function. Ensure TURNSTILE_SECRET_KEY (or the relevant env var referenced in turnstile-config.ts) is set in all deployment environments.

Testing Notes for Reviewers

1. Support form happy path: Open the SupportModal, fill out the form, and submit. Verify the Turnstile widget renders (may be invisible/managed mode), the token is sent with the request, and the server validates it successfully.
2. CAPTCHA failure: Simulate an invalid/missing Turnstile token (e.g., by intercepting the request in DevTools and removing the token). Confirm the API returns an appropriate error and the UI handles it gracefully.
3. Import integrity: Verify no broken imports exist — run the build (next build) to catch any missing module references.
4. Repository pages: Navigate to pages using ActiveSubscriptions and BrowseRepositories to confirm no regressions from the cleanup.
5. Environment config: Confirm the Turnstile site key is correctly loaded client-side and the secret key is available server-side.

Browser Compatibility Considerations

• Cloudflare Turnstile supports all modern browsers (Chrome, Firefox, Safari, Edge). No IE11 support is provided by Turnstile, which aligns with typical Next.js application targets.
• The Turnstile JS SDK is loaded externally from Cloudflare's CDN — ensure CSP (Content Security Policy) headers allow https://challenges.cloudflare.com if a strict CSP is in place.
• No other browser-specific concerns; all other changes are standard React/Next.js patterns.

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🤖 Generated with Claude Code

Branch Info:

• Source: chore/cleanup-repo-pages
• Target: main
• Type: feature

Co-Authored-By: Claude noreply@anthropic.com