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>

server/src/routes/integrations.ts

@@ -19,6 +19,7 @@ import { createGiteaAdapter } from "../integrations/gitea/adapter.js";
 import { createDockhandAdapter } from "../integrations/dockhand/adapter.js";
 import { createSemaphoreAdapter } from "../integrations/semaphore/adapter.js";
 import { createProxmoxAdapter } from "../integrations/proxmox/adapter.js";
+import { createSynologyAdapter } from "../integrations/synology/adapter.js";
 import { asyncHandler } from "../utils/asyncHandler.js";
 
 export const integrationsRouter = Router();
@@ -614,3 +615,44 @@ for (const action of proxmoxActions) {
     }),
   );
 }
+
+// ─── Synology ────────────────────────────────────────────────────────────────
+// Read-only per the delivery plan — no start/stop/etc actions.
+
+async function requireSynologyAdapter(req: Request, res: Response) {
+  const id = Number(req.params.id);
+  const loaded = await loadIntegrationConfig(id);
+  if (!loaded) {
+    res.status(404).json({ error: "not_found" });
+    return null;
+  }
+  if (loaded.integration.type !== "synology") {
+    res.status(400).json({ error: "wrong_type" });
+    return null;
+  }
+  if (!loaded.integration.enabled) {
+    res.status(400).json({ error: "integration_disabled" });
+    return null;
+  }
+  return { integration: loaded.integration, adapter: createSynologyAdapter(loaded.config as any) };
+}
+
+integrationsRouter.get("/:id/synology/storage", asyncHandler(async (req, res) => {
+  const found = await requireSynologyAdapter(req, res);
+  if (!found) return;
+
+  try {
+    const info = await found.adapter.getStorageInfo();
+    res.json({
+      ...info,
+      summary: {
+        volumeCount: info.volumes.length,
+        volumesNotNormal: info.volumes.filter((v) => v.status !== "normal").length,
+        diskCount: info.disks.length,
+        disksNotNormal: info.disks.filter((d) => d.status !== "normal").length,
+      },
+    });
+  } catch (err) {
+    res.status(502).json({ error: err instanceof Error ? err.message : String(err) });
+  }
+}));