fix(interactive): honour --dry-run flag in single-agent interactive path (#2184)

When a user ran `spawn claude --dry-run`, the dry-run flag was silently
ignored and a real server was provisioned. `cmdAgentInteractive` was
passing `dryRun` in the `debug` parameter position of `execScript`, so
no preview was shown and `SPAWN_DEBUG=1` was set instead.

Fix:
- Export `showDryRunPreview` from `run.ts`
- Import and call it in `cmdAgentInteractive` after cloud selection
- Return early when `dryRun` is set (matches `cmdRun` behaviour)
- Pass `undefined` for the `debug` argument (interactive path has no
  debug flag)

Agent: code-health

Co-authored-by: B <6723574+louisgv@users.noreply.github.com>
Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>

packages/cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@openrouter/spawn",
-  "version": "0.12.16",
+  "version": "0.12.17",
   "type": "module",
   "bin": {
     "spawn": "cli.js"

packages/cli/src/commands/interactive.ts

@@ -15,7 +15,7 @@ import {
   preflightCredentialCheck,
   getAuthHint,
 } from "./shared.js";
-import { execScript } from "./run.js";
+import { execScript, showDryRunPreview } from "./run.js";
 
 // Prompt user to select an agent with hints and type-ahead filtering
 async function selectAgent(manifest: Manifest): Promise<string> {
@@ -170,6 +170,11 @@ export async function cmdAgentInteractive(agent: string, prompt?: string, dryRun
   const { clouds, hintOverrides } = getAndValidateCloudChoices(manifest, resolvedAgent);
   const cloudChoice = await selectCloud(manifest, clouds, hintOverrides);
 
+  if (dryRun) {
+    showDryRunPreview(manifest, resolvedAgent, cloudChoice, prompt);
+    return;
+  }
+
   await preflightCredentialCheck(manifest, cloudChoice);
 
   const spawnName = await promptSpawnName();
@@ -186,7 +191,7 @@ export async function cmdAgentInteractive(agent: string, prompt?: string, dryRun
     prompt,
     getAuthHint(manifest, cloudChoice),
     manifest.clouds[cloudChoice].url,
-    dryRun,
+    undefined,
     spawnName,
   );
 }

packages/cli/src/commands/run.ts

@@ -170,7 +170,7 @@ function buildPromptLines(prompt: string): string[] {
   return lines;
 }
 
-function showDryRunPreview(manifest: Manifest, agent: string, cloud: string, prompt?: string): void {
+export function showDryRunPreview(manifest: Manifest, agent: string, cloud: string, prompt?: string): void {
   p.log.info(pc.bold("Dry run -- no resources will be provisioned\n"));
 
   printDryRunSection("Agent", buildAgentLines(manifest.agents[agent]));