feat: catalogue enrichment — tagline, genres, warnings, quality score, batch covers

Backend (handlers_catalogue.go):
- POST /api/admin/text-gen/tagline — 1-sentence marketing hook
- POST /api/admin/text-gen/genres + /apply — LLM genre suggestions, editable + persist
- POST /api/admin/text-gen/content-warnings — mature theme detection
- POST /api/admin/text-gen/quality-score — 1–5 description quality rating
- POST /api/admin/catalogue/batch-covers (SSE) — generate covers for books missing one
- POST /api/admin/catalogue/batch-covers/cancel — cancel via in-memory job registry
- POST /api/admin/catalogue/refresh-metadata/{slug} (SSE) — description + cover refresh

Frontend:
- text-gen: 4 new tabs (Tagline, Genres, Warnings, Quality) with book autocomplete
- image-gen: localStorage style presets (save/apply/delete named prompt templates)
- catalogue-tools: new admin page with batch cover SSE progress + cancel
- admin nav: "Catalogue Tools" link added

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

ui/src/routes/api/admin/catalogue/batch-covers/+server.ts

@@ -0,0 +1,43 @@
+/**
+ * POST /api/admin/catalogue/batch-covers
+ *
+ * Admin-only SSE proxy to the Go backend's batch cover generation endpoint.
+ * Pipes the stream straight through so the browser can consume it without buffering.
+ */
+import { 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 ({ request, locals }) => {
+	if (!locals.user || locals.user.role !== 'admin') {
+		throw error(403, 'Forbidden');
+	}
+	const body = await request.text();
+	let res: Response;
+	try {
+		res = await backendFetch('/api/admin/catalogue/batch-covers', {
+			method: 'POST',
+			headers: { 'content-type': 'application/json' },
+			body
+		});
+	} catch (e) {
+		log.error('admin/catalogue/batch-covers', 'backend proxy error', { err: String(e) });
+		throw error(502, 'Could not reach backend');
+	}
+	if (!res.ok) {
+		const data = await res.json().catch(() => ({}));
+		return new Response(JSON.stringify(data), {
+			status: res.status,
+			headers: { 'Content-Type': 'application/json' }
+		});
+	}
+	return new Response(res.body, {
+		status: 200,
+		headers: {
+			'Content-Type': 'text/event-stream',
+			'Cache-Control': 'no-cache',
+			'X-Accel-Buffering': 'no'
+		}
+	});
+};

ui/src/routes/api/admin/catalogue/batch-covers/cancel/+server.ts

@@ -0,0 +1,24 @@
+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 ({ request, locals }) => {
+	if (!locals.user || locals.user.role !== 'admin') {
+		throw error(403, 'Forbidden');
+	}
+	const body = await request.text();
+	let res: Response;
+	try {
+		res = await backendFetch('/api/admin/catalogue/batch-covers/cancel', {
+			method: 'POST',
+			headers: { 'content-type': 'application/json' },
+			body
+		});
+	} catch (e) {
+		log.error('admin/catalogue/batch-covers/cancel', 'backend proxy error', { 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/admin/catalogue/refresh-metadata/[slug]/+server.ts

@@ -0,0 +1,41 @@
+/**
+ * POST /api/admin/catalogue/refresh-metadata/[slug]
+ *
+ * Admin-only SSE proxy — re-generates description + cover for a single book.
+ */
+import { error } from '@sveltejs/kit';
+import type { RequestHandler } from './$types';
+import { log } from '$lib/server/logger';
+import { backendFetch } from '$lib/server/scraper';
+
+export const POST: RequestHandler = async ({ params, locals }) => {
+	if (!locals.user || locals.user.role !== 'admin') {
+		throw error(403, 'Forbidden');
+	}
+	let res: Response;
+	try {
+		res = await backendFetch(`/api/admin/catalogue/refresh-metadata/${params.slug}`, {
+			method: 'POST',
+			headers: { 'content-type': 'application/json' },
+			body: '{}'
+		});
+	} catch (e) {
+		log.error('admin/catalogue/refresh-metadata', 'backend proxy error', { err: String(e) });
+		throw error(502, 'Could not reach backend');
+	}
+	if (!res.ok) {
+		const data = await res.json().catch(() => ({}));
+		return new Response(JSON.stringify(data), {
+			status: res.status,
+			headers: { 'Content-Type': 'application/json' }
+		});
+	}
+	return new Response(res.body, {
+		status: 200,
+		headers: {
+			'Content-Type': 'text/event-stream',
+			'Cache-Control': 'no-cache',
+			'X-Accel-Buffering': 'no'
+		}
+	});
+};

ui/src/routes/api/admin/text-gen/content-warnings/+server.ts

@@ -0,0 +1,24 @@
+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 ({ request, locals }) => {
+	if (!locals.user || locals.user.role !== 'admin') {
+		throw error(403, 'Forbidden');
+	}
+	const body = await request.text();
+	let res: Response;
+	try {
+		res = await backendFetch('/api/admin/text-gen/content-warnings', {
+			method: 'POST',
+			headers: { 'content-type': 'application/json' },
+			body
+		});
+	} catch (e) {
+		log.error('admin/text-gen/content-warnings', 'backend proxy error', { 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/admin/text-gen/genres/+server.ts

@@ -0,0 +1,24 @@
+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 ({ request, locals }) => {
+	if (!locals.user || locals.user.role !== 'admin') {
+		throw error(403, 'Forbidden');
+	}
+	const body = await request.text();
+	let res: Response;
+	try {
+		res = await backendFetch('/api/admin/text-gen/genres', {
+			method: 'POST',
+			headers: { 'content-type': 'application/json' },
+			body
+		});
+	} catch (e) {
+		log.error('admin/text-gen/genres', 'backend proxy error', { 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/admin/text-gen/genres/apply/+server.ts

@@ -0,0 +1,24 @@
+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 ({ request, locals }) => {
+	if (!locals.user || locals.user.role !== 'admin') {
+		throw error(403, 'Forbidden');
+	}
+	const body = await request.text();
+	let res: Response;
+	try {
+		res = await backendFetch('/api/admin/text-gen/genres/apply', {
+			method: 'POST',
+			headers: { 'content-type': 'application/json' },
+			body
+		});
+	} catch (e) {
+		log.error('admin/text-gen/genres/apply', 'backend proxy error', { 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/admin/text-gen/quality-score/+server.ts

@@ -0,0 +1,24 @@
+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 ({ request, locals }) => {
+	if (!locals.user || locals.user.role !== 'admin') {
+		throw error(403, 'Forbidden');
+	}
+	const body = await request.text();
+	let res: Response;
+	try {
+		res = await backendFetch('/api/admin/text-gen/quality-score', {
+			method: 'POST',
+			headers: { 'content-type': 'application/json' },
+			body
+		});
+	} catch (e) {
+		log.error('admin/text-gen/quality-score', 'backend proxy error', { 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/admin/text-gen/tagline/+server.ts

@@ -0,0 +1,24 @@
+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 ({ request, locals }) => {
+	if (!locals.user || locals.user.role !== 'admin') {
+		throw error(403, 'Forbidden');
+	}
+	const body = await request.text();
+	let res: Response;
+	try {
+		res = await backendFetch('/api/admin/text-gen/tagline', {
+			method: 'POST',
+			headers: { 'content-type': 'application/json' },
+			body
+		});
+	} catch (e) {
+		log.error('admin/text-gen/tagline', 'backend proxy error', { err: String(e) });
+		throw error(502, 'Could not reach backend');
+	}
+	const data = await res.json().catch(() => ({}));
+	return json(data, { status: res.status });
+};