chore: migrate to v3, Doppler secrets, clean up legacy code

- Remove all pre-v3 code: scraper, ui-v2, backend v1, ios v1+v2, legacy CI workflows
- Flatten v3/ contents to repo root
- Add Doppler secrets management (project=libnovel, config=prd)
- Add justfile with doppler run wrappers for all docker compose commands
- Strip hardcoded env fallbacks from docker-compose.yml
- Add minimal README.md
- Clean up .gitignore

ui/src/routes/api/profile/avatar/+server.ts

@@ -1,65 +1,56 @@
 import { json, error } from '@sveltejs/kit';
 import type { RequestHandler } from './$types';
-import { presignAvatarUploadUrl, presignAvatarUrl } from '$lib/server/minio';
+import { presignAvatarUrl } from '$lib/server/minio';
 import { updateUserAvatarUrl, getUserByUsername } from '$lib/server/pocketbase';
+import { backendFetch } from '$lib/server/scraper';
 
 const ALLOWED_TYPES = ['image/jpeg', 'image/png', 'image/webp'];
 
 /**
  * POST /api/profile/avatar
- * Body: JSON { mime_type: "image/jpeg" | "image/png" | "image/webp" }
+ * Body: raw image bytes (Content-Type: image/jpeg | image/png | image/webp)
  *
- * Returns a short-lived presigned PUT URL pointing at MinIO (public endpoint)
- * so the client can upload the image bytes directly, bypassing the server.
- * After the PUT completes, the client must call PATCH /api/profile/avatar
- * with the returned key to record it in PocketBase.
- *
- * Returns: { upload_url: string, key: string }
- */
-export const POST: RequestHandler = async ({ request, locals }) => {
-	if (!locals.user) error(401, 'Not authenticated');
-
-	let mimeType = 'image/jpeg';
-	try {
-		const body = await request.json();
-		if (body?.mime_type) mimeType = body.mime_type;
-	} catch {
-		// default to jpeg if body is missing/invalid
-	}
-
-	if (!ALLOWED_TYPES.includes(mimeType)) {
-		error(400, `Unsupported image type: ${mimeType}. Allowed: jpeg, png, webp`);
-	}
-
-	const { uploadUrl, key } = await presignAvatarUploadUrl(locals.user.id, mimeType);
-	return json({ upload_url: uploadUrl, key });
-};
-
-/**
- * PATCH /api/profile/avatar
- * Body: JSON { key: string }
- *
- * Called after the client has successfully PUT the image to MinIO via the
- * presigned URL. Records the object key in PocketBase and returns a fresh
+ * Uploads the image to MinIO via the Go backend (server-to-server, no browser
+ * → MinIO direct upload), records the key in PocketBase, and returns a fresh
  * presigned GET URL for immediate display.
  *
  * Returns: { avatar_url: string | null }
  */
-export const PATCH: RequestHandler = async ({ request, locals }) => {
+export const POST: RequestHandler = async ({ request, locals }) => {
 	if (!locals.user) error(401, 'Not authenticated');
 
-	let key: string | undefined;
-	try {
-		const body = await request.json();
-		if (typeof body?.key === 'string') key = body.key;
-	} catch {
-		error(400, 'Invalid JSON body');
+	const ct = request.headers.get('Content-Type') ?? '';
+	// Strip parameters (e.g. "image/jpeg; charset=utf-8" → "image/jpeg")
+	const mimeType = ct.split(';')[0].trim();
+
+	if (!ALLOWED_TYPES.includes(mimeType)) {
+		error(400, `Unsupported image type. Allowed: image/jpeg, image/png, image/webp`);
 	}
 
-	if (!key) error(400, 'Missing "key" field');
+	// Read the raw body
+	const blob = await request.arrayBuffer();
+	if (blob.byteLength === 0) error(400, 'Empty image body');
+	if (blob.byteLength > 5 * 1024 * 1024) error(413, 'Image too large (max 5 MiB)');
 
+	// Forward directly to Go backend — server-to-server, so internal MinIO is reachable.
+	const uploadRes = await backendFetch(
+		`/api/avatar-upload/${encodeURIComponent(locals.user.id)}`,
+		{
+			method: 'PUT',
+			headers: { 'Content-Type': mimeType },
+			body: blob
+		}
+	);
+	if (!uploadRes.ok) {
+		const text = await uploadRes.text().catch(() => '');
+		error(uploadRes.status as 400 | 500, `Upload failed: ${text || uploadRes.statusText}`);
+	}
+	const { key } = (await uploadRes.json()) as { key: string };
+
+	// Record object key in PocketBase.
 	await updateUserAvatarUrl(locals.user.id, key);
 
+	// Return a fresh presigned GET URL for immediate display.
 	const avatarUrl = await presignAvatarUrl(locals.user.id);
 	return json({ avatar_url: avatarUrl });
 };