refactor(desktop): split kernel_commands/pipeline_commands into modules, add SaaS client libs and gateway modules

Split monolithic kernel_commands.rs (2185 lines) and pipeline_commands.rs (1391 lines)
into focused sub-modules under kernel_commands/ and pipeline_commands/ directories.
Add gateway module (commands, config, io, runtime), health_check, and 15 new
TypeScript client libraries for SaaS relay, auth, admin, telemetry, and kernel
sub-systems (a2a, agent, chat, hands, skills, triggers).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

desktop/src/lib/kernel-a2a.ts

@@ -0,0 +1,59 @@
+/**
+ * kernel-a2a.ts - Agent-to-Agent (A2A) methods for KernelClient
+ *
+ * Installed onto KernelClient.prototype via installA2aMethods().
+ */
+
+import { invoke } from '@tauri-apps/api/core';
+import type { KernelClient } from './kernel-client';
+
+export function installA2aMethods(ClientClass: { prototype: KernelClient }): void {
+  const proto = ClientClass.prototype as any;
+
+  // ─── A2A (Agent-to-Agent) API ───
+
+  /**
+   * Send a direct A2A message from one agent to another
+   */
+  proto.a2aSend = async function (this: KernelClient, from: string, to: string, payload: unknown, messageType?: string): Promise<void> {
+    await invoke('agent_a2a_send', {
+      from,
+      to,
+      payload,
+      messageType: messageType || 'notification',
+    });
+  };
+
+  /**
+   * Broadcast a message from an agent to all other agents
+   */
+  proto.a2aBroadcast = async function (this: KernelClient, from: string, payload: unknown): Promise<void> {
+    await invoke('agent_a2a_broadcast', { from, payload });
+  };
+
+  /**
+   * Discover agents that have a specific capability
+   */
+  proto.a2aDiscover = async function (this: KernelClient, capability: string): Promise<Array<{
+    id: string;
+    name: string;
+    description: string;
+    capabilities: Array<{ name: string; description: string }>;
+    role: string;
+    priority: number;
+  }>> {
+    return await invoke('agent_a2a_discover', { capability });
+  };
+
+  /**
+   * Delegate a task to another agent and wait for response
+   */
+  proto.a2aDelegateTask = async function (this: KernelClient, from: string, to: string, task: string, timeoutMs?: number): Promise<unknown> {
+    return await invoke('agent_a2a_delegate_task', {
+      from,
+      to,
+      task,
+      timeoutMs: timeoutMs || 30000,
+    });
+  };
+}