Enhance social image security and visual aesthetics

[kargig]

Implement critical security patches and advanced visual refinements for the social image overlay feature. This includes robust authorization via media IDs, top-tier SSRF protection, and high-end visualization features.

Backend:

• Fix 403 Forbidden error for dive owners by implementing media_id based lookup, resolving mismatches between presigned URLs and stored paths.
• Implement "Trusted Source" SSRF protection: outbound requests now use URLs retrieved from database records rather than raw user input.
• Harden SSRF protection via URL canonicalization and by disabling HTTP redirects at the request sink.
• Refactor profile visualization to use a transparent gradient fill clamped by a mask, allowing the background photo to remain visible.
• Implement a vertical depth axis with overlaid labels (0m and Max Depth) integrated directly into the profile chart.
• Optimize vertical positioning of the watermark URL and profile chart to prevent visual overlap and ensure a balanced composition.
• Improve metadata rendering with drop shadows and icon-based metrics.

Frontend:

• Update SocialShareModal and socialHelpers to pass media_id to the API.
• Fix ESLint import order errors for a clean build.

Testing:

• Expand automated test suite to 9 comprehensive cases covering all security, authorization, and data parsing scenarios.
• Verify robust handling of numeric and complex string-based dive profile data.