diff --git a/.claude/CLAUDE.md b/.claude/CLAUDE.md
deleted file mode 120000
index ff807266877..00000000000
--- a/.claude/CLAUDE.md
+++ /dev/null
@@ -1 +0,0 @@
-../.github/copilot-instructions.md
\ No newline at end of file
diff --git a/.claude/skills/launch b/.claude/skills/launch
deleted file mode 120000
index b41e2b420ad..00000000000
--- a/.claude/skills/launch
+++ /dev/null
@@ -1 +0,0 @@
-../../.agents/skills/launch
\ No newline at end of file
diff --git a/.gitignore b/.gitignore
index e5ca4dd32cc..65cb1937168 100644
--- a/.gitignore
+++ b/.gitignore
@@ -30,21 +30,16 @@ test/componentFixtures/.screenshots/*
 !test/componentFixtures/.screenshots/baseline/
 dist
 .playwright-cli
+.claude/
 .agents/agents/*.local.md
-.claude/agents/*.local.md
 .github/agents/*.local.md
 .agents/agents/*.local.agent.md
-.claude/agents/*.local.agent.md
 .github/agents/*.local.agent.md
 .agents/hooks/*.local.json
-.claude/hooks/*.local.json
 .github/hooks/*.local.json
 .agents/instructions/*.local.instructions.md
-.claude/instructions/*.local.instructions.md
 .github/instructions/*.local.instructions.md
 .agents/prompts/*.local.prompt.md
-.claude/prompts/*.local.prompt.md
 .github/prompts/*.local.prompt.md
 .agents/skills/.local/
-.claude/skills/.local/
 .github/skills/.local/
diff --git a/build/npm/postinstall.ts b/build/npm/postinstall.ts
index ae2651cd188..5ab9d682857 100644
--- a/build/npm/postinstall.ts
+++ b/build/npm/postinstall.ts
@@ -288,6 +288,37 @@ async function main() {
 
 	fs.writeFileSync(stateFile, JSON.stringify(_state));
 	fs.writeFileSync(stateContentsFile, JSON.stringify(computeContents()));
+
+	// Symlink .claude/ files to their canonical locations to test Claude agent harness
+	const claudeDir = path.join(root, '.claude');
+	fs.mkdirSync(claudeDir, { recursive: true });
+
+	const claudeMdLink = path.join(claudeDir, 'CLAUDE.md');
+	if (!fs.existsSync(claudeMdLink)) {
+		fs.symlinkSync(path.join('..', '.github', 'copilot-instructions.md'), claudeMdLink);
+		log('.', 'Symlinked .claude/CLAUDE.md -> .github/copilot-instructions.md');
+	}
+
+	const claudeSkillsLink = path.join(claudeDir, 'skills');
+	if (!fs.existsSync(claudeSkillsLink)) {
+		fs.symlinkSync(path.join('..', '.agents', 'skills'), claudeSkillsLink);
+		log('.', 'Symlinked .claude/skills -> .agents/skills');
+	}
+
+	// Temporary: patch @github/copilot-sdk session.js to fix ESM import
+	// (missing .js extension on vscode-jsonrpc/node). Fixed upstream in v0.1.32.
+	// TODO: Remove once @github/copilot-sdk is updated to >=0.1.32
+	for (const dir of ['', 'remote']) {
+		const sessionFile = path.join(root, dir, 'node_modules', '@github', 'copilot-sdk', 'dist', 'session.js');
+		if (fs.existsSync(sessionFile)) {
+			const content = fs.readFileSync(sessionFile, 'utf8');
+			const patched = content.replace(/from "vscode-jsonrpc\/node"/g, 'from "vscode-jsonrpc/node.js"');
+			if (content !== patched) {
+				fs.writeFileSync(sessionFile, patched);
+				log(dir || '.', 'Patched @github/copilot-sdk session.js (vscode-jsonrpc ESM import fix)');
+			}
+		}
+	}
 }
 
 main().catch(err => {