Add adapter environment testing infrastructure

Introduce testEnvironment() on ServerAdapterModule with structured
pass/warn/fail diagnostics for all four adapter types (claude_local,
codex_local, process, http). Adds POST test-environment endpoint,
shared types/validators, adapter test implementations, and UI API
client. Includes asset type foundations used by related features.

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

packages/adapters/codex-local/src/server/test.ts

@@ -0,0 +1,95 @@
+import type {
+  AdapterEnvironmentCheck,
+  AdapterEnvironmentTestContext,
+  AdapterEnvironmentTestResult,
+} from "@paperclip/adapter-utils";
+import {
+  asString,
+  parseObject,
+  ensureAbsoluteDirectory,
+  ensureCommandResolvable,
+  ensurePathInEnv,
+} from "@paperclip/adapter-utils/server-utils";
+
+function summarizeStatus(checks: AdapterEnvironmentCheck[]): AdapterEnvironmentTestResult["status"] {
+  if (checks.some((check) => check.level === "error")) return "fail";
+  if (checks.some((check) => check.level === "warn")) return "warn";
+  return "pass";
+}
+
+function isNonEmpty(value: unknown): value is string {
+  return typeof value === "string" && value.trim().length > 0;
+}
+
+export async function testEnvironment(
+  ctx: AdapterEnvironmentTestContext,
+): Promise<AdapterEnvironmentTestResult> {
+  const checks: AdapterEnvironmentCheck[] = [];
+  const config = parseObject(ctx.config);
+  const command = asString(config.command, "codex");
+  const cwd = asString(config.cwd, process.cwd());
+
+  try {
+    await ensureAbsoluteDirectory(cwd);
+    checks.push({
+      code: "codex_cwd_valid",
+      level: "info",
+      message: `Working directory is valid: ${cwd}`,
+    });
+  } catch (err) {
+    checks.push({
+      code: "codex_cwd_invalid",
+      level: "error",
+      message: err instanceof Error ? err.message : "Invalid working directory",
+      detail: cwd,
+    });
+  }
+
+  const envConfig = parseObject(config.env);
+  const env: Record<string, string> = {};
+  for (const [key, value] of Object.entries(envConfig)) {
+    if (typeof value === "string") env[key] = value;
+  }
+  const runtimeEnv = ensurePathInEnv({ ...process.env, ...env });
+  try {
+    await ensureCommandResolvable(command, cwd, runtimeEnv);
+    checks.push({
+      code: "codex_command_resolvable",
+      level: "info",
+      message: `Command is executable: ${command}`,
+    });
+  } catch (err) {
+    checks.push({
+      code: "codex_command_unresolvable",
+      level: "error",
+      message: err instanceof Error ? err.message : "Command is not executable",
+      detail: command,
+    });
+  }
+
+  const configOpenAiKey = env.OPENAI_API_KEY;
+  const hostOpenAiKey = process.env.OPENAI_API_KEY;
+  if (isNonEmpty(configOpenAiKey) || isNonEmpty(hostOpenAiKey)) {
+    const source = isNonEmpty(configOpenAiKey) ? "adapter config env" : "server environment";
+    checks.push({
+      code: "codex_openai_api_key_present",
+      level: "info",
+      message: "OPENAI_API_KEY is set for Codex authentication.",
+      detail: `Detected in ${source}.`,
+    });
+  } else {
+    checks.push({
+      code: "codex_openai_api_key_missing",
+      level: "warn",
+      message: "OPENAI_API_KEY is not set. Codex runs may fail until authentication is configured.",
+      hint: "Set OPENAI_API_KEY in adapter env, shell environment, or Codex auth configuration.",
+    });
+  }
+
+  return {
+    adapterType: ctx.adapterType,
+    status: summarizeStatus(checks),
+    checks,
+    testedAt: new Date().toISOString(),
+  };
+}