Allow the checked-in triage dashboard canvas to open without pre-supplied state

Problem

The checked-in openclaw-triage-dashboard canvas on main cannot be opened directly by another developer when no input object is supplied.

Observed error:

Failed to open canvas
RPC error -32603: Request session.canvas.open failed with message: Invalid input for canvas "openclaw-triage-dashboard" open input: (root): "schemaVersion" is a required property; (root): "repo" is a required property; (root): "title" is a required property; (root): "scope" is a required property; (root): "generatedAt" is a required property (+1 more). Inspect the canvas declaration for the expected input schema.

Expected behavior

A developer should be able to open the checked-in canvas from the repository without first constructing and supplying a complete triage-state object. The canvas should either load a checked-in/default state, provide an empty-state/bootstrap flow, or expose a clearly supported file/import path.

Reproduction

1. Check out current main.
2. Load the project extension.
3. Open the openclaw-triage-dashboard canvas without supplying custom input.
4. Observe schema validation failure before the canvas opens.

Acceptance criteria

• Direct canvas opening from the checked-in repository succeeds without a caller-authored state object.
• The initial surface explains how to load or generate triage state when none exists.
• Existing explicit, schema-versioned state input remains supported.
• Tests cover both direct no-input opening and explicit-state opening.
• GitHub mutations remain read-only and confirmation-gated.

Start by inspecting the checked-in openclaw-triage-dashboard canvas declaration and its input schema, then locate the existing explicit-state opening path and test entry points. Add a supported no-input or bootstrap flow while preserving schema-versioned state input, and cover both opening modes plus read-only, confirmation-gated mutations.