feat: add allowlisted host view for plugins

An allowlist rather than a list of fields to strip. A blocklist rots:
the moment a new secret-bearing column lands on SSHHost it starts
leaking silently. With an allowlist a new field stays invisible to
plugins until someone adds it here on purpose.

src/backend/plugins/host-view.ts

@@ -0,0 +1,68 @@
+/**
+ * The only shape of a host a plugin ever sees.
+ *
+ * This is an ALLOWLIST, deliberately, not a list of fields to strip. A
+ * blocklist rots: the moment someone adds a new secret-bearing column to
+ * SSHHost, a blocklist silently starts leaking it, and nothing fails. With an
+ * allowlist a new field is invisible to plugins until someone consciously adds
+ * it here.
+ *
+ * resolveHostById returns an object carrying password, key, keyPassword,
+ * certPublicKey, sudoPassword and the autostart* secrets in plaintext. None of
+ * them are in this list, and none of them may ever be.
+ */
+
+export interface PluginHostView {
+  id: number;
+  name: string | null;
+  ip: string;
+  port: number;
+  username: string;
+  folder: string | null;
+  tags: string[];
+  authType: string | null;
+  enableTerminal: boolean;
+  enableTunnel: boolean;
+  enableFileManager: boolean;
+  createdAt: string | null;
+  updatedAt: string | null;
+}
+
+const NUMBER_FIELDS = ["id", "port"] as const;
+const STRING_FIELDS = [
+  "name",
+  "ip",
+  "username",
+  "folder",
+  "authType",
+  "createdAt",
+  "updatedAt",
+] as const;
+const BOOLEAN_FIELDS = [
+  "enableTerminal",
+  "enableTunnel",
+  "enableFileManager",
+] as const;
+
+export function toPluginHostView(
+  host: Record<string, unknown>,
+): PluginHostView {
+  const view: Record<string, unknown> = {};
+
+  for (const field of NUMBER_FIELDS) {
+    view[field] = Number(host[field] ?? 0);
+  }
+  for (const field of STRING_FIELDS) {
+    const value = host[field];
+    view[field] = typeof value === "string" ? value : null;
+  }
+  for (const field of BOOLEAN_FIELDS) {
+    view[field] = Boolean(host[field]);
+  }
+
+  view.tags = Array.isArray(host.tags)
+    ? host.tags.filter((tag): tag is string => typeof tag === "string")
+    : [];
+
+  return view as unknown as PluginHostView;
+}