fix(install): forward --target to additive apm install (non-isolated)

dist/index.js

@@ -41921,7 +41921,7 @@ async function run() {
             // Install extra inline deps additively
             if (depsInput) {
                 const deps = parseDependencies(depsInput);
-                await installDeps(resolvedDir, deps);
+                await installDeps(resolvedDir, deps, validatedTarget);
             }
         }
         // Run content audit if report requested
@@ -42064,23 +42064,29 @@ function parseDependencies(input) {
 }
 /**
  * Install dependencies additively via `apm install <dep>`.
+ *
+ * If `target` is provided it is forwarded as `--target <target>` so APM
+ * v0.12.3+ strict harness detection has an explicit signal. Without it,
+ * additive installs into a workspace with no harness markers
+ * (`.github/copilot-instructions.md`, `.claude/`, `CLAUDE.md`, etc.) exit
+ * with code 2.
  */
-async function installDeps(dir, deps) {
+async function installDeps(dir, deps, target) {
     lib_core/* info */.pq(`Installing ${deps.length} inline dependencies...`);
+    const targetArgs = target ? ['--target', target] : [];
     for (const dep of deps) {
         if (typeof dep === 'string') {
-            await runApm(['install', dep], dir);
+            await runApm(['install', dep, ...targetArgs], dir);
         }
         else {
-            // Object-form: build the install argument
             let installArg = dep.git;
             if (dep.path) {
                 installArg += `#path=${dep.path}`;
             }
             if (dep.ref) {
                 installArg += (installArg.includes('#') ? '&' : '#') + `ref=${dep.ref}`;
             }
-            await runApm(['install', installArg], dir);
+            await runApm(['install', installArg, ...targetArgs], dir);
         }
     }
 }

src/__tests__/runner.test.ts

@@ -321,6 +321,39 @@ describe('run', () => {
     expect(mockSetFailed).not.toHaveBeenCalled();
   });
 
+  it('forwards --target to additive apm install (non-isolated mode)', async () => {
+    // Regression: APM v0.12.3+ rejects `apm install <pkg>` with exit 2
+    // ("No harness detected") when the workspace has no harness markers.
+    // The non-isolated additive path (apm.yml absent, inline deps present)
+    // must forward the action's `target` input as `--target <value>` on
+    // every per-dep install call, mirroring what isolated mode does via
+    // the generated apm.yml.
+    const installCalls: string[][] = [];
+    mockExec.mockImplementation((cmd: string, args?: string[]) => {
+      if (cmd === 'apm' && args?.[0] === 'install') installCalls.push(args);
+      return Promise.resolve(0);
+    });
+
+    mockGetInput.mockImplementation((name: unknown) => {
+      switch (name) {
+        case 'working-directory': return tmpDir;
+        case 'dependencies': return 'microsoft/apm-sample-package';
+        case 'isolated': return 'false';
+        case 'target': return 'copilot';
+        case 'pack': return 'false';
+        case 'compile': return 'false';
+        default: return '';
+      }
+    });
+
+    await run();
+
+    expect(mockSetFailed).not.toHaveBeenCalled();
+    expect(installCalls).toEqual([
+      ['install', 'microsoft/apm-sample-package', '--target', 'copilot'],
+    ]);
+  });
+
   it('fails fast when working directory does not exist in non-isolated mode', async () => {
     const nonExistentDir = path.join(tmpDir, 'does-not-exist');
 

src/runner.ts

@@ -323,7 +323,7 @@ export async function run(): Promise<void> {
       // Install extra inline deps additively
       if (depsInput) {
         const deps = parseDependencies(depsInput);
-        await installDeps(resolvedDir, deps);
+        await installDeps(resolvedDir, deps, validatedTarget);
       }
     }
 
@@ -490,22 +490,28 @@ function parseDependencies(input: string): Dependency[] {
 
 /**
  * Install dependencies additively via `apm install <dep>`.
+ *
+ * If `target` is provided it is forwarded as `--target <target>` so APM
+ * v0.12.3+ strict harness detection has an explicit signal. Without it,
+ * additive installs into a workspace with no harness markers
+ * (`.github/copilot-instructions.md`, `.claude/`, `CLAUDE.md`, etc.) exit
+ * with code 2.
  */
-async function installDeps(dir: string, deps: Dependency[]): Promise<void> {
+async function installDeps(dir: string, deps: Dependency[], target?: string): Promise<void> {
   core.info(`Installing ${deps.length} inline dependencies...`);
+  const targetArgs = target ? ['--target', target] : [];
   for (const dep of deps) {
     if (typeof dep === 'string') {
-      await runApm(['install', dep], dir);
+      await runApm(['install', dep, ...targetArgs], dir);
     } else {
-      // Object-form: build the install argument
       let installArg = dep.git;
       if (dep.path) {
         installArg += `#path=${dep.path}`;
       }
       if (dep.ref) {
         installArg += (installArg.includes('#') ? '&' : '#') + `ref=${dep.ref}`;
       }
-      await runApm(['install', installArg], dir);
+      await runApm(['install', installArg, ...targetArgs], dir);
     }
   }
 }