feat(service-integrations): phase 1 — integration architecture foundation

- Add Integration interfaces, registry, cache, encryption, and base helpers
- Add integrationType, integrationConfig, integrationEnabled to App model
- Add integration widget type to constants and validators
- Add integration fields to AppRecord, CreateAppInput, UpdateAppInput
- Update appService with encryption/decryption for integration config
- Add API routes: list integrations, test connection, fetch endpoint data

src/routes/api/integrations/+server.ts

@@ -0,0 +1,15 @@
+import { json } from '@sveltejs/kit';
+import type { RequestHandler } from './$types';
+import { requireAuth } from '$lib/server/middleware/authenticate.js';
+import { listInfo } from '$lib/server/integrations/registry.js';
+import { success } from '$lib/server/utils/response.js';
+
+/**
+ * GET /api/integrations — List available integration types.
+ */
+export const GET: RequestHandler = async (event) => {
+	requireAuth(event);
+
+	const integrations = listInfo();
+	return json(success(integrations));
+};

src/routes/api/integrations/test/+server.ts

@@ -0,0 +1,46 @@
+import { json } from '@sveltejs/kit';
+import type { RequestHandler } from './$types';
+import { z } from 'zod';
+import { requireAuth } from '$lib/server/middleware/authenticate.js';
+import * as registry from '$lib/server/integrations/registry.js';
+import { success, error } from '$lib/server/utils/response.js';
+
+const testConnectionSchema = z.object({
+	integrationType: z.string().min(1, 'Integration type is required'),
+	appUrl: z.string().url('Invalid app URL'),
+	config: z.record(z.unknown())
+});
+
+/**
+ * POST /api/integrations/test — Test an integration connection.
+ */
+export const POST: RequestHandler = async (event) => {
+	requireAuth(event);
+
+	let body: unknown;
+	try {
+		body = await event.request.json();
+	} catch {
+		return json(error('Invalid JSON body'), { status: 400 });
+	}
+
+	const parsed = testConnectionSchema.safeParse(body);
+	if (!parsed.success) {
+		return json(error(parsed.error.errors[0]?.message ?? 'Invalid input'), { status: 400 });
+	}
+
+	const { integrationType, appUrl, config } = parsed.data;
+
+	const integration = registry.get(integrationType);
+	if (!integration) {
+		return json(error(`Unknown integration type: ${integrationType}`), { status: 404 });
+	}
+
+	try {
+		const result = await integration.testConnection(appUrl, config);
+		return json(success(result));
+	} catch (err) {
+		const message = err instanceof Error ? err.message : 'Connection test failed';
+		return json(error(message), { status: 500 });
+	}
+};