Standardize TinyNode route contract across consumers (/app/* vs root)

[cubap]

During contract-seam scanning across CDH repos, I found a route-shape mismatch risk across TinyNode consumers:

• deer uses /app/create, /app/query, /app/update, /app/overwrite
• TPEN-services appears to use root routes /create, /query, /update, /overwrite, /delete

Recommended adjustment:

1. Document canonical TinyNode API surface and supported aliases.
2. Publish OpenAPI for TinyNode routes (including /app/* and root aliases if both are supported).
3. Add compatibility tests ensuring both consumer patterns continue to work, or explicitly deprecate one pattern with migration guidance.

Why this matters:

• Divergent route prefixes/method expectations increase break risk across consumers.

Filed by automation as requested; label: copilot.