fix: support virtual-hosted S3 URLs for avatar storage (#330)

Avatar images failed to load with 403 on Tigris and newer AWS S3 buckets
because getAvatarUrl only constructed path-style URLs. Modern S3-compatible
providers require virtual-hosted URLs (bucket.domain/key).

Add NEXT_PUBLIC_STORAGE_DOMAIN env var to signal URL style:
- If set: virtual-hosted URL (Tigris, AWS S3)
- If not set: path-style URL (MinIO, LocalStack) - backward compatible

Add vitest and tests for getAvatarUrl behavior.

Co-authored-by: Sachin Divekar <sachin.divekar@remiges.tech>

apps/web/package.json

@@ -10,6 +10,8 @@
     "format": "prettier --check . --ignore-path ../../.gitignore",
     "lint": "eslint",
     "start": "pnpm with-env next start",
+    "test": "vitest run",
+    "test:watch": "vitest",
     "typecheck": "tsc --noEmit",
     "with-env": "dotenv -e ../../.env --",
     "lingui:extract": "lingui extract",
@@ -86,7 +88,8 @@
     "jiti": "^1.21.6",
     "prettier": "catalog:",
     "tailwindcss": "catalog:",
-    "typescript": "catalog:"
+    "typescript": "catalog:",
+    "vitest": "^3.0.0"
   },
   "prettier": "@kan/prettier-config"
 }