docs: update .env.template with write test environment variables

.env.template

@@ -2,10 +2,17 @@ BITBUCKET_MCP_EMAIL=your_email@example.com
 BITBUCKET_MCP_TOKEN=your_api_token
 DEFAULT_WORKSPACE=your-workspace
 DEFAULT_REPO=your-repo
+RUN_WRITE_TESTS=true
+TEST_PR_ID=123
 
 # Integration test write operations
+# ---------------------------------------------------------------------------------
 # Set RUN_WRITE_TESTS=true to enable tests that create/modify/delete data.
+#
 # TEST_PR_ID must also be set — write tests will only run against this specific PR
 # to avoid accidentally modifying unrelated pull requests.
+# ---------------------------------------------------------------------------------
+# Example:
 # RUN_WRITE_TESTS=true
 # TEST_PR_ID=123
+# ---------------------------------------------------------------------------------