feat(integrations): add Gotify notifications integration (#5847)

* feat(integrations): add Gotify notifications integration

Closes #4186

> "It would be really useful if Homarr could integrate with Gotify —
> view notifications from Gotify right inside the Homarr dashboard,
> maybe as a widget or a small panel. A widget that displays the latest
> messages from Gotify (with title, message, time)."
> — #4186: feat: Gotify Integration - display notifications in Homarr

- `gotify/gotify-schema.ts` — Zod schema validating the `GET /message`
  API response from the Gotify server, including id, date, title,
  message body, and optional priority fields.
- `gotify/gotify-integration.ts` — `GotifyIntegration` class extending
  the base `Integration` and implementing `INotificationsIntegration`.
  Authenticates via HTTP Basic Auth (username + password) and fetches
  the latest 100 messages from the `/message` endpoint. Connection
  testing hits `/health`.
- `index.ts` — exports `GotifyIntegration` from the package public API.
- `base/creator.ts` — registers `GotifyIntegration` in the integration
  creator map so it can be instantiated at runtime.

- `integration.ts` — registers the `gotify` integration definition with:
  - `secretKinds: [["username", "password"]]` (Basic Auth credentials)
  - `category: ["notifications"]` (picked up automatically by the
    Notifications widget via `getIntegrationKindsByCategory`)
  - Icon sourced from `homarr-labs/dashboard-icons`
  - Documentation URL pointing to `/docs/integrations/gotify`
- `docs/homarr-docs-sitemap.ts` — adds `/docs/integrations/gotify` to
  the `HomarrDocumentationPath` union type so the documentation link
  passes the TypeScript path validation check.

Because `gotify` is registered under the `notifications` category, the
existing Notifications widget automatically supports it with no widget
code changes required. Users add the integration via Settings →
Integrations, supply their Gotify server URL, username, and password,
then attach it to a Notifications widget on any board.

* refactor(integrations): inline json parse and add error handling in Gotify integration

Address PR review feedback: remove intermediate `as unknown` cast by inlining
response.json() directly, and use safeParseAsync to handle deserialization
failures gracefully instead of throwing unhandled.

packages/integrations/src/gotify/gotify-integration.ts

@@ -0,0 +1,41 @@
+import { ResponseError } from "@homarr/common/server";
+import { fetchWithTrustedCertificatesAsync } from "@homarr/core/infrastructure/http";
+
+import { Integration } from "../base/integration";
+import type { IntegrationTestingInput } from "../base/integration";
+import type { TestingResult } from "../base/test-connection/test-connection-service";
+import type { Notification } from "../interfaces/notifications/notification-types";
+import type { INotificationsIntegration } from "../interfaces/notifications/notifications-integration";
+import { gotifyMessagesResponseSchema } from "./gotify-schema";
+
+export class GotifyIntegration extends Integration implements INotificationsIntegration {
+  public async testingAsync(input: IntegrationTestingInput): Promise<TestingResult> {
+    await input.fetchAsync(this.url("/health"), { headers: this.getHeaders() });
+    return { success: true };
+  }
+
+  private getHeaders() {
+    const credentials = Buffer.from(
+      `${super.getSecretValue("username")}:${super.getSecretValue("password")}`,
+    ).toString("base64");
+    return { Authorization: `Basic ${credentials}` };
+  }
+
+  public async getNotificationsAsync(): Promise<Notification[]> {
+    const url = this.url("/message", { limit: 100 });
+    const response = await fetchWithTrustedCertificatesAsync(url, { headers: this.getHeaders() });
+
+    if (!response.ok) throw new ResponseError(response);
+
+    const result = await gotifyMessagesResponseSchema.safeParseAsync(await response.json());
+    if (!result.success) throw new Error(`Failed to parse Gotify response: ${result.error.message}`);
+    const parsed = result.data;
+
+    return parsed.messages.map((message): Notification => ({
+      id: String(message.id),
+      time: new Date(message.date),
+      title: message.title,
+      body: message.message,
+    }));
+  }
+}

packages/integrations/src/gotify/gotify-schema.ts

@@ -0,0 +1,14 @@
+import { z } from "zod/v4";
+
+// See: https://gotify.net/api-docs#/message/getMessages
+export const gotifyMessageSchema = z.object({
+  id: z.number(),
+  date: z.string(),
+  title: z.string(),
+  message: z.string(),
+  priority: z.number().optional(),
+});
+
+export const gotifyMessagesResponseSchema = z.object({
+  messages: z.array(gotifyMessageSchema),
+});