Unlink servers before deleting a Proxmox integration

servers.proxmox_integration_id was created (migration 0001) without an ON DELETE
rule, although schema.ts asks for "set null", so with foreign keys on, deleting
an integration that a server was linked to failed with a constraint error.
The delete route now clears the four proxmox_* columns on those servers first
and records how many it unlinked in the audit entry. schema.ts notes the gap.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

server/src/db/schema.ts

@@ -224,7 +224,9 @@ export const servers = sqliteTable("servers", {
   lastPortScan: text("last_port_scan"), // JSON string: summary of the most recent network scan from this app
   tags: text("tags"), // JSON string: string[] — free-form labels for grouping and filtering, normalized by services/serverTags
 
-  // Optional link to a Proxmox VM/LXC — set by an admin, not the agent.
+  // Optional link to a Proxmox VM/LXC — set by an admin, not the agent. The "set null" below is what this file asks for,
+  // but migration 0001 created the column without it, so the database itself has no ON DELETE rule here: deleting an
+  // integration clears these columns in routes/integrations.ts instead. (See DATABASE.md.)
   proxmoxIntegrationId: integer("proxmox_integration_id").references(() => integrations.id, {
     onDelete: "set null",
   }),

server/src/routes/integrations.ts

@@ -272,6 +272,14 @@ integrationsRouter.delete("/:id", requireRole("admin"), asyncHandler(async (req,
     return res.status(404).json({ error: "not_found" });
   }
 
+  // servers.proxmox_integration_id was meant to clear itself, but the database only has a plain REFERENCES on it (see
+  // DATABASE.md), so a linked server would block the delete. Clear the whole link here — the four columns go together.
+  const unlinked = await db
+    .update(servers)
+    .set({ proxmoxIntegrationId: null, proxmoxNode: null, proxmoxGuestType: null, proxmoxVmid: null })
+    .where(eq(servers.proxmoxIntegrationId, id))
+    .returning({ id: servers.id });
+
   await db.delete(integrations).where(eq(integrations.id, id));
   if (existing.credentialId) {
     await db.delete(integrationCredentials).where(eq(integrationCredentials.id, existing.credentialId));
@@ -283,7 +291,7 @@ integrationsRouter.delete("/:id", requireRole("admin"), asyncHandler(async (req,
     action: "delete",
     targetType: "integration",
     targetId: id,
-    detail: { name: existing.name },
+    detail: { name: existing.name, ...(unlinked.length > 0 ? { unlinkedServers: unlinked.length } : {}) },
   });
 
   res.status(204).end();