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/base/creator.ts

@@ -35,6 +35,7 @@ import { MockIntegration } from "../mock/mock-integration";
 import { NavidromeIntegration } from "../navidrome/navidrome-integration";
 import { NextcloudIntegration } from "../nextcloud/nextcloud.integration";
 import { NPMIntegration } from "../npm/npm-integration";
+import { GotifyIntegration } from "../gotify/gotify-integration";
 import { NTFYIntegration } from "../ntfy/ntfy-integration";
 import { OpenMediaVaultIntegration } from "../openmediavault/openmediavault-integration";
 import { OPNsenseIntegration } from "../opnsense/opnsense-integration";
@@ -121,6 +122,7 @@ export const integrationCreators = {
   ical: ICalIntegration,
   quay: QuayIntegration,
   ntfy: NTFYIntegration,
+  gotify: GotifyIntegration,
   mock: MockIntegration,
   truenas: TrueNasIntegration,
   unraid: UnraidIntegration,