feat: ship host metrics as a first-party in-process plugin

plugins/host-metrics/backend/widgets/processes-collector.ts

@@ -0,0 +1,68 @@
+import type { Client } from "ssh2";
+import { execCommand } from "../../../../src/backend/hosts/metrics-shared/common-utils.js";
+
+export async function collectProcessesMetrics(client: Client): Promise<{
+  total: number | null;
+  running: number | null;
+  top: Array<{
+    pid: string;
+    user: string;
+    cpu: string;
+    mem: string;
+    command: string;
+  }>;
+}> {
+  let totalProcesses: number | null = null;
+  let runningProcesses: number | null = null;
+  const topProcesses: Array<{
+    pid: string;
+    user: string;
+    cpu: string;
+    mem: string;
+    command: string;
+  }> = [];
+
+  try {
+    const psOut = await execCommand(
+      client,
+      "(ps aux --sort=-%cpu 2>/dev/null || ps aux) | head -n 11",
+    );
+    const psLines = psOut.stdout
+      .split("\n")
+      .map((l) => l.trim())
+      .filter(Boolean);
+    if (psLines.length > 1) {
+      for (let i = 1; i < Math.min(psLines.length, 11); i++) {
+        const parts = psLines[i].split(/\s+/);
+        if (parts.length >= 11) {
+          const cpuVal = Number(parts[2]);
+          const memVal = Number(parts[3]);
+          topProcesses.push({
+            pid: parts[1],
+            user: parts[0],
+            cpu: Number.isFinite(cpuVal) ? cpuVal.toString() : "0",
+            mem: Number.isFinite(memVal) ? memVal.toString() : "0",
+            command: parts.slice(10).join(" ").substring(0, 50),
+          });
+        }
+      }
+    }
+
+    const procCount = await execCommand(client, "ps aux | wc -l");
+    const runningCount = await execCommand(client, "ps aux | grep -c ' R '");
+
+    const totalCount = Number(procCount.stdout.trim()) - 1;
+    totalProcesses = Number.isFinite(totalCount) ? totalCount : null;
+
+    const runningCount2 = Number(runningCount.stdout.trim());
+    runningProcesses = Number.isFinite(runningCount2) ? runningCount2 : null;
+  } catch {
+    // expected
+  }
+
+  return {
+    total: totalProcesses,
+    running: runningProcesses,
+    top: topProcesses,
+  };
+}