fix(coding-agent): display path of sibling dependent extensions (#6964)

fixes: #6619

packages/coding-agent/src/modes/interactive/interactive-mode.ts

@@ -1077,8 +1077,16 @@ export class InteractiveMode {
 	 * Get a short path relative to the package root for display.
 	 */
 	private getShortPath(fullPath: string, sourceInfo?: SourceInfo): string {
+		const normalizedFullPath = fullPath.replace(/\\/g, "/");
 		const baseDir = sourceInfo?.baseDir;
 		if (baseDir && this.isPackageSource(sourceInfo)) {
+			const normalizedBaseDir = baseDir.replace(/\\/g, "/");
+			const npmRootMatch = normalizedBaseDir.match(/^(.*\/node_modules)\/(@?[^/]+(?:\/[^/]+)?)$/);
+			// If fullPath is under the same node_modules root as baseDir, preserve that relative topology.
+			if (npmRootMatch?.[1] && normalizedFullPath.startsWith(`${npmRootMatch[1]}/`)) {
+				return path.posix.relative(normalizedBaseDir, normalizedFullPath);
+			}
+
 			const relativePath = path.relative(path.resolve(baseDir), path.resolve(fullPath));
 			if (
 				relativePath &&
@@ -1092,12 +1100,12 @@ export class InteractiveMode {
 		}
 
 		const source = sourceInfo?.source ?? "";
-		const npmMatch = fullPath.match(/node_modules\/(@?[^/]+(?:\/[^/]+)?)\/(.*)/);
+		const npmMatch = normalizedFullPath.match(/node_modules\/(@?[^/]+(?:\/[^/]+)?)\/(.*)/);
 		if (npmMatch && source.startsWith("npm:")) {
 			return npmMatch[2];
 		}
 
-		const gitMatch = fullPath.match(/git\/[^/]+\/[^/]+\/(.*)/);
+		const gitMatch = normalizedFullPath.match(/git\/[^/]+\/[^/]+\/(.*)/);
 		if (gitMatch && source.startsWith("git:")) {
 			return gitMatch[1];
 		}

packages/coding-agent/test/interactive-mode-status.test.ts

@@ -1019,6 +1019,84 @@ describe("InteractiveMode.showLoadedResources", () => {
 "[Extensions]
   pi-markdown-preview"`);
 	});
+
+	test("labels npm sibling extensions relative to the declaring package", () => {
+		const extensions: ExtensionFixture[] = [
+			{
+				path: "/tmp/project/.pi/npm/node_modules/primary-package/index.ts",
+				sourceInfo: createSourceInfo("/tmp/project/.pi/npm/node_modules/primary-package/index.ts", {
+					source: "npm:primary-package",
+					scope: "project",
+					origin: "package",
+					baseDir: "/tmp/project/.pi/npm/node_modules/primary-package",
+				}),
+			},
+			{
+				path: "/tmp/project/.pi/npm/node_modules/sibling-package/index.ts",
+				sourceInfo: createSourceInfo("/tmp/project/.pi/npm/node_modules/sibling-package/index.ts", {
+					source: "npm:primary-package",
+					scope: "project",
+					origin: "package",
+					baseDir: "/tmp/project/.pi/npm/node_modules/primary-package",
+				}),
+			},
+		];
+
+		const fakeThis = createShowLoadedResourcesThis({
+			quietStartup: false,
+			extensions,
+			useRealScopeGroups: true,
+		});
+
+		(InteractiveMode as any).prototype.showLoadedResources.call(fakeThis, {
+			force: false,
+		});
+
+		expect(normalizeRenderedOutput(fakeThis.loadedResourcesContainer)).toMatchInlineSnapshot(`
+"[Extensions]
+  primary-package, primary-package:../sibling-package"`);
+	});
+
+	test("labels Windows npm sibling extensions relative to the declaring package", () => {
+		const primaryPath = "C:\\Users\\me\\.pi\\agent\\npm\\node_modules\\primary-package\\index.ts";
+		const siblingPath = "C:\\Users\\me\\.pi\\agent\\npm\\node_modules\\sibling-package\\index.ts";
+		const baseDir = "C:\\Users\\me\\.pi\\agent\\npm\\node_modules\\primary-package";
+		const extensions: ExtensionFixture[] = [
+			{
+				path: primaryPath,
+				sourceInfo: createSourceInfo(primaryPath, {
+					source: "npm:primary-package",
+					scope: "user",
+					origin: "package",
+					baseDir,
+				}),
+			},
+			{
+				path: siblingPath,
+				sourceInfo: createSourceInfo(siblingPath, {
+					source: "npm:primary-package",
+					scope: "user",
+					origin: "package",
+					baseDir,
+				}),
+			},
+		];
+
+		const fakeThis = createShowLoadedResourcesThis({
+			quietStartup: false,
+			extensions,
+			useRealScopeGroups: true,
+		});
+
+		(InteractiveMode as any).prototype.showLoadedResources.call(fakeThis, {
+			force: false,
+		});
+
+		expect(normalizeRenderedOutput(fakeThis.loadedResourcesContainer)).toMatchInlineSnapshot(`
+"[Extensions]
+  primary-package, primary-package:../sibling-package"`);
+	});
+
 	test("captures mixed extension layouts in expanded output", () => {
 		const fakeThis = createShowLoadedResourcesThis({
 			quietStartup: false,