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/scrape/+server.ts

@@ -1,7 +1,7 @@
 /**
  * POST /api/scrape
  *
- * Proxies scrape requests to the Go scraper backend.
+ * Proxies scrape requests to the Go backend.
  * Admin-only — returns 403 if the authenticated user is not an admin.
  *
  * Request body (JSON):
@@ -17,10 +17,8 @@
 
 import { json, error } from '@sveltejs/kit';
 import type { RequestHandler } from './$types';
-import { env } from '$env/dynamic/private';
 import { log } from '$lib/server/logger';
-
-const SCRAPER_URL = env.SCRAPER_API_URL ?? 'http://localhost:8080';
+import { backendFetch } from '$lib/server/scraper';
 
 export const POST: RequestHandler = async ({ request, locals }) => {
 	// Admin guard
@@ -39,26 +37,25 @@ export const POST: RequestHandler = async ({ request, locals }) => {
 	const isBookScrape = typeof body.url === 'string' && body.url.length > 0;
 	const endpoint = isBookScrape ? '/scrape/book' : '/scrape';
 
-	const upstream = `${SCRAPER_URL}${endpoint}`;
 	let res: Response;
 	try {
-		res = await fetch(upstream, {
+		res = await backendFetch(endpoint, {
 			method: 'POST',
 			headers: { 'Content-Type': 'application/json' },
 			body: isBookScrape ? JSON.stringify({ url: body.url }) : undefined
 		});
 	} catch (e) {
-		log.error('scrape', 'scraper proxy network error', { endpoint, err: String(e) });
-		throw error(502, 'Could not reach scraper');
+		log.error('scrape', 'backend proxy network error', { endpoint, err: String(e) });
+		throw error(502, 'Could not reach backend');
 	}
 
 	if (!res.ok && res.status >= 500) {
 		const text = await res.text().catch(() => '');
-		log.error('scrape', 'scraper returned error', { endpoint, status: res.status, body: text });
+		log.error('scrape', 'backend returned error', { endpoint, status: res.status, body: text });
 	}
 
 	const data = await res.json().catch(() => ({}));
 
-	// Pass through the status code from the Go scraper (202, 409, 400, …)
+	// Pass through the status code from the Go backend (202, 409, 400, …)
 	return json(data, { status: res.status });
 };

ui/src/routes/api/scrape/cancel/[id]/+server.ts

@@ -0,0 +1,40 @@
+/**
+ * POST /api/scrape/cancel/[id]
+ *
+ * Admin-only proxy that cancels a pending scrape (or audio) task by ID.
+ * Forwards the request to the Go backend POST /api/cancel-task/{id}.
+ *
+ * Responses:
+ *   200  OK       — task cancelled
+ *   403  Forbidden — not an admin
+ *   409  Conflict  — task cannot be cancelled (already running/done/not found)
+ */
+
+import { json, error } from '@sveltejs/kit';
+import type { RequestHandler } from './$types';
+import { log } from '$lib/server/logger';
+import { backendFetch } from '$lib/server/scraper';
+
+export const POST: RequestHandler = async ({ params, locals }) => {
+	if (!locals.user || locals.user.role !== 'admin') {
+		throw error(403, 'Forbidden');
+	}
+
+	const { id } = params;
+	if (!id) {
+		throw error(400, 'Missing task id');
+	}
+
+	let res: Response;
+	try {
+		res = await backendFetch(`/api/cancel-task/${encodeURIComponent(id)}`, {
+			method: 'POST'
+		});
+	} catch (e) {
+		log.error('scrape/cancel', 'network error cancelling task', { id, err: String(e) });
+		throw error(502, 'Could not reach backend');
+	}
+
+	const data = await res.json().catch(() => ({}));
+	return json(data, { status: res.status });
+};

ui/src/routes/api/scrape/range/+server.ts

@@ -1,7 +1,7 @@
 /**
  * POST /api/scrape/range
  *
- * Proxies range-scrape requests to the Go scraper backend at POST /scrape/book/range.
+ * Proxies range-scrape requests to the Go backend at POST /scrape/book/range.
  * Admin-only.
  *
  * Request body (JSON):
@@ -17,10 +17,8 @@
 
 import { json, error } from '@sveltejs/kit';
 import type { RequestHandler } from './$types';
-import { env } from '$env/dynamic/private';
 import { log } from '$lib/server/logger';
-
-const SCRAPER_URL = env.SCRAPER_API_URL ?? 'http://localhost:8080';
+import { backendFetch } from '$lib/server/scraper';
 
 export const POST: RequestHandler = async ({ request, locals }) => {
 	// Admin guard
@@ -39,22 +37,21 @@ export const POST: RequestHandler = async ({ request, locals }) => {
 		throw error(400, 'url and from are required');
 	}
 
-	const upstream = `${SCRAPER_URL}/scrape/book/range`;
 	let res: Response;
 	try {
-		res = await fetch(upstream, {
+		res = await backendFetch('/scrape/book/range', {
 			method: 'POST',
 			headers: { 'Content-Type': 'application/json' },
 			body: JSON.stringify({ url: body.url, from: body.from, to: body.to })
 		});
 	} catch (e) {
-		log.error('scrape/range', 'scraper proxy network error', { err: String(e) });
-		throw error(502, 'Could not reach scraper');
+		log.error('scrape/range', 'backend proxy network error', { err: String(e) });
+		throw error(502, 'Could not reach backend');
 	}
 
 	if (!res.ok && res.status >= 500) {
 		const text = await res.text().catch(() => '');
-		log.error('scrape/range', 'scraper returned error', { status: res.status, body: text });
+		log.error('scrape/range', 'backend returned error', { status: res.status, body: text });
 	}
 
 	const data = await res.json().catch(() => ({}));

ui/src/routes/api/scrape/task/[id]/+server.ts

@@ -0,0 +1,19 @@
+import { json, error } from '@sveltejs/kit';
+import type { RequestHandler } from './$types';
+import { getScrapingTask } from '$lib/server/pocketbase';
+
+/**
+ * GET /api/scrape/task/[id]
+ *
+ * Returns { id, status, error_message } for a single scraping task.
+ * Used by the book detail page to poll for task completion.
+ */
+export const GET: RequestHandler = async ({ params }) => {
+	const { id } = params;
+	if (!id) throw error(400, 'Missing task id');
+
+	const task = await getScrapingTask(id).catch(() => null);
+	if (!task) throw error(404, 'Task not found');
+
+	return json({ id: task.id, status: task.status, error_message: task.error_message ?? '' });
+};