D3: Populate VS Code content block description field

[Arithmomaniac]

Parent: #54

Problem

CLI sets content block description to the tool name (e.g., view, grep); VS Code leaves it None. While the HTML template doesn't use description directly, the _match_tool_for_block preprocessing function may benefit from it for more accurate tool-to-block matching.

Change

In _process_response_items() line 234, pass the toolId as the description in the raw_blocks tuple:

raw_blocks.append(("toolInvocation", msg_text, None)) → raw_blocks.append(("toolInvocation", msg_text, tool_id))

Where tool_id comes from the toolInvocationSerialized item's toolId field.

Scope

1 line in src/copilot_session_tools/scanner/vscode.py