Adds support for custom text and image background

[Parajulibkrm]

Summary

This PR adds configurable OG image customization across all progress endpoints:

• Adds support for a custom background image via query param (backgroundImageUrl) for /api/days, /api/months, and /api/current-month.
• Adds configurable black tint overlay alpha via query param (overlayAlpha, clamped to 0..1) and applies it across the full image canvas.
• Adds optional custom handle text (handleText) rendered directly below progressText in the same visual style.
• Updates OG rendering composition to use layered full-canvas background + overlay + foreground content, improving reliability of tinting and image placement behavior.

Query Params Added

• backgroundImageUrl — URL of background image
• overlayAlpha — black overlay intensity (0 to 1)
• handleText — custom text shown below progress text

Files Changed

• lib/og_image.tsx
  • Added OgRenderOptions and OgTextOptions
  • Added request URL parsers for render/text options
  • Updated createOgImageResponse() to support background image + full-image overlay composition
• lib/generator.ts
  • Added optional textOptions to all grid generators
  • Added conditional handle text node beneath progress text in matching style
• app/api/days/route.tsx
• app/api/months/route.tsx
• app/api/current-month/route.tsx
  • Parse and pass render/text options to generator + OG response helpers

[vercel]

@Parajulibkrm is attempting to deploy a commit to the bimsina's projects Team on Vercel.

A member of the Team first needs to authorize it.