Extract adapter registry across CLI, server, and UI

Refactor monolithic heartbeat service, AgentConfigForm, and CLI
heartbeat-run into a proper adapter registry pattern. Each adapter
type (process, claude-local, codex-local, http) gets its own module
with server-side execution logic, CLI invocation, and UI config form.
Significantly reduces file sizes and enables adding new adapters
without touching core code.

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

server/src/adapters/http/execute.ts

@@ -0,0 +1,42 @@
+import type { AdapterExecutionContext, AdapterExecutionResult } from "../types.js";
+import { asString, asNumber, parseObject } from "../utils.js";
+
+export async function execute(ctx: AdapterExecutionContext): Promise<AdapterExecutionResult> {
+  const { config, runId, agent, context } = ctx;
+  const url = asString(config.url, "");
+  if (!url) throw new Error("HTTP adapter missing url");
+
+  const method = asString(config.method, "POST");
+  const timeoutMs = asNumber(config.timeoutMs, 15000);
+  const headers = parseObject(config.headers) as Record<string, string>;
+  const payloadTemplate = parseObject(config.payloadTemplate);
+  const body = { ...payloadTemplate, agentId: agent.id, runId, context };
+
+  const controller = new AbortController();
+  const timer = setTimeout(() => controller.abort(), timeoutMs);
+
+  try {
+    const res = await fetch(url, {
+      method,
+      headers: {
+        "content-type": "application/json",
+        ...headers,
+      },
+      body: JSON.stringify(body),
+      signal: controller.signal,
+    });
+
+    if (!res.ok) {
+      throw new Error(`HTTP invoke failed with status ${res.status}`);
+    }
+
+    return {
+      exitCode: 0,
+      signal: null,
+      timedOut: false,
+      summary: `HTTP ${method} ${url}`,
+    };
+  } finally {
+    clearTimeout(timer);
+  }
+}