Add Synology integration — completes all six planned live integrations

Sixth and final live integration: volume and disk health across the NAS,
read-only per the delivery plan (DSM write actions are riskier and stayed
out of scope). Adapter built against the same discover-then-call pattern
used by hacf-fr/synologydsm-api (the library behind Home Assistant's
Synology integration) since DSM's API paths/versions vary by release and
the user's NAS isn't reachable from here to check directly:
- GET query.cgi?api=SYNO.API.Info&method=query&query=all once per adapter
  instance, to learn the real path/version for SYNO.API.Auth and
  SYNO.Storage.CGI.Storage rather than hardcoding them
- SYNO.API.Auth login (account/passwd/format=sid) for a session id, re-used
  across calls and refreshed on session-related error codes (105/106/119)
- SYNO.Storage.CGI.Storage's `load_info` method, which returns disks,
  volumes, and pools in one call — verified against that library's
  storage.py field mapping (size.total/used, status, smart_status, temp,
  exceed_bad_sector_thr, below_remain_life_thr)

Uses node:https directly (like Proxmox and the cPanel DNS adapter) for an
"allow self-signed certificate" option, since DSM ships one by default.
No 2FA support — login surfaces a clear error if the account requires it
rather than failing silently.

Verified: full build passes. Unreachable from here, so ran an 11-check HTTP
test against the live server: confirms all six integration types are now
registered, role gating, credential (password) non-leakage, disabled-
integration blocking, and the wrong_type crash-safety check — server stays
up throughout. Real volume/disk data still needs verification once this app
can reach the user's NAS.

This completes the integrations phase from the original plan: Tailscale,
Gitea, Dockhand, Semaphore, Proxmox, Synology are all built, each following
the same config-in-UI + encrypted-credentials pattern. Combined with the
foundation, Secrets, IPAM, DNS, and Servers & Tasks modules from earlier,
Homelab Manager now covers every feature area from the user's original
request.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

web/src/api/client.ts

@@ -290,6 +290,31 @@ export interface ProxmoxGuestsResponse {
   summary: { total: number; running: number };
 }
 
+export interface SynologyVolume {
+  id: string;
+  status: string;
+  deviceType: string;
+  sizeTotal: number | null;
+  sizeUsed: number | null;
+}
+
+export interface SynologyDisk {
+  id: string;
+  name: string;
+  device: string;
+  status: string;
+  smartStatus: string;
+  temp: number | null;
+  exceedBadSectorThreshold: boolean;
+  belowRemainLifeThreshold: boolean;
+}
+
+export interface SynologyStorageResponse {
+  volumes: SynologyVolume[];
+  disks: SynologyDisk[];
+  summary: { volumeCount: number; volumesNotNormal: number; diskCount: number; disksNotNormal: number };
+}
+
 export class UnauthorizedError extends Error {}
 export class ForbiddenError extends Error {}
 
@@ -505,5 +530,8 @@ export const api = {
       restart: (integrationId: number, node: string, type: ProxmoxGuestType, vmid: number) =>
         request<void>(`/api/integrations/${integrationId}/proxmox/nodes/${node}/${type}/${vmid}/restart`, { method: "POST" }),
     },
+    synology: {
+      storage: (integrationId: number) => request<SynologyStorageResponse>(`/api/integrations/${integrationId}/synology/storage`),
+    },
   },
 };