Follow the snake_case rename outside the test tree

CI's inline "Test CLI and MCP protocol" step and the IDE-integration
setup script both read `.isError` off a CallToolResult. mcp 2.x renamed
model fields to snake_case, so both needed `.is_error`. My earlier sweep
only covered tests/ and rmcp/, which is why CI caught these and I did
not.

Deliberately unchanged: scripts/testing/test-local.sh and
scripts/test-claude-connector.py also mention isError/structuredContent,
but those index raw JSON-RPC response dicts, where camelCase is the wire
format and still correct.

Verified by running CI's script verbatim against a real stdio server.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: soodoku

.github/workflows/ci.yml

@@ -474,7 +474,7 @@ jobs:
                         "summary_stats",
                         {"data": {"x": [1, 2, 3, 4, 5]}, "variables": ["x"]},
                     )
-                    assert not result.isError, result.content
+                    assert not result.is_error, result.content
                     print(f"MCP stdio OK: {len(names)} tools, summary_stats ran")
 
 

scripts/setup/ide_integrations.py

@@ -352,7 +352,7 @@ async def run_analysis():
         except Exception as e:
             pytest.fail(f"Sample analysis failed: {e}")
 
-        assert not result.isError, f"Sample analysis returned error: {result.content}"
+        assert not result.is_error, f"Sample analysis returned error: {result.content}"
         print("Sample analysis successful")