Add profile_photos table with client-side resize

[bobbythelobster]

Summary

Resolves #61

Profile photos for Nametags were being uploaded at full resolution and rendered at 120×120px — a huge bandwidth waste. This PR adds a profile_photos table and client-side image processing to serve properly sized images.

How it works

Zero-cost client-side resizing

Photos are resized in the browser using the Canvas API before upload. No server-side image processing needed. Three sizes are produced:

Size	Max Dimension	Use Case
thumb	120×120	Nametag avatar
medium	300×300	Profile view (default)
original	800×800	High-res fallback

All variants are converted to WebP for optimal file size.

Hash-based deduplication

Each original image is SHA-256 hashed before upload. If the same image has been uploaded before, the existing versions are reused — no duplicate storage.

Storage layout

Inside the avatars bucket:

photos/{hash}/thumb.webp
photos/{hash}/medium.webp
photos/{hash}/original.webp

Backward compatible

Existing profile_photo URLs continue to work. The Nametag component uses the optimized thumb URL when a photo_id hash is available, falling back to the legacy URL otherwise.

Changes

New files

• supabase/migrations/20260204000000_create_profile_photos.sql — Creates profile_photos table + adds photo_id FK to profiles
• lib/imageUtils.ts — Client-side image hashing and resizing utilities
• lib/photoService.ts — Upload service with dedup + multi-size storage + URL helpers

Modified files

• app/components/Nametag.tsx — Uses optimized thumb URL when hash available
• app/setup/page.tsx — Uses new upload flow, stores photo_id
• app/whois/ProfileDisplay.tsx — Uses new upload flow, stores photo_id
• app/whois/ProfileList.tsx — Loads photo_id, passes to Nametag
• app/whois/page.tsx — Loads photo_id from profile data

Migration notes

After merging, run the Supabase migration to create the profile_photos table and add the photo_id column to profiles. Existing profiles will have photo_id = NULL and continue using their legacy profile_photo URLs.