refactor(agent): dedupe harness and command workflows

src/agents/skills-install.ts

@@ -6,6 +6,7 @@ import { runCommandWithTimeout, type CommandOptions } from "../process/exec.js";
 import { scanDirectoryWithSummary } from "../security/skill-scanner.js";
 import { resolveUserPath } from "../utils.js";
 import { installDownloadSpec } from "./skills-install-download.js";
+import { formatInstallFailureMessage } from "./skills-install-output.js";
 import {
   hasBinary,
   loadWorkspaceSkillEntries,
@@ -32,45 +33,6 @@ export type SkillInstallResult = {
   warnings?: string[];
 };
 
-function summarizeInstallOutput(text: string): string | undefined {
-  const raw = text.trim();
-  if (!raw) {
-    return undefined;
-  }
-  const lines = raw
-    .split("\n")
-    .map((line) => line.trim())
-    .filter(Boolean);
-  if (lines.length === 0) {
-    return undefined;
-  }
-
-  const preferred =
-    lines.find((line) => /^error\b/i.test(line)) ??
-    lines.find((line) => /\b(err!|error:|failed)\b/i.test(line)) ??
-    lines.at(-1);
-
-  if (!preferred) {
-    return undefined;
-  }
-  const normalized = preferred.replace(/\s+/g, " ").trim();
-  const maxLen = 200;
-  return normalized.length > maxLen ? `${normalized.slice(0, maxLen - 1)}…` : normalized;
-}
-
-function formatInstallFailureMessage(result: {
-  code: number | null;
-  stdout: string;
-  stderr: string;
-}): string {
-  const code = typeof result.code === "number" ? `exit ${result.code}` : "unknown exit";
-  const summary = summarizeInstallOutput(result.stderr) ?? summarizeInstallOutput(result.stdout);
-  if (!summary) {
-    return `Install failed (${code})`;
-  }
-  return `Install failed (${code}): ${summary}`;
-}
-
 function withWarnings(result: SkillInstallResult, warnings: string[]): SkillInstallResult {
   if (warnings.length === 0) {
     return result;