feat: display no-order M1 shadow suggestions

[Pigbibi]

Summary

• add a dedicated authenticated source route and read-only M1 Shadow summary to the unified console
• validate upstream decision authority, no-order declaration, and zero proposed weights before storing the source snapshot
• visually separate M1 Shadow evidence from research tasks and execution evidence

Safety

• uses a dedicated adaptive-selection sync token, not a control-plane token
• no dispatch, platform switch, broker call, or order action is added
• source aggregation is stale-aware and remains no-order even when a source is unavailable

Validation

• node tests/strategy_switch_worker_validation.mjs passed locally
• git diff check passed
• GitHub CI will run JS, Python, and workflow checks