fix(web): preserve PicoClaw tool feedback rendering

[GatewayJ]

• Keep legacy PicoClaw tool feedback messages in Markdown rendering when they start with the wrench prefix.
• Limit extracted JSON promotion to explicit CSGClaw envelope payloads such as csgclaw.action_card and csgclaw.notify_card.
• Add regression coverage for action-card extraction and PicoClaw tool feedback rendering.
• Root cause: generic JSON extraction promoted PicoClaw tool feedback JSON into structured cards and hid the wrench-style rendering.
• Validation: pnpm --dir web/app test -- tests/components/MessageContent.test.tsx tests/components/MessageContent/structuredMessages.test.ts.
• Validation: pnpm --dir web/app typecheck.
• Note: local validation emitted the existing Node engine warning because this environment ran Node v26 while the package declares >=22.13.0 <25.