Adopt PolyForm noncommercial licensing

[SarashaElion]

Summary

This PR replaces the TRIA SDK's AGPL posture with the licensing model established for the Institute-owned SDK:

• PolyForm Noncommercial License 1.0.0 for noncommercial use
• Separate written commercial license from Trivian Institute for commercial use

Changes

• updates the README license section to state that the SDK is source-available for noncommercial use and that commercial use requires a separate license from Trivian Institute
• replaces LICENSE.md with a PolyForm Noncommercial 1.0.0 notice, official controlling terms URL, required copyright notice, and explicit commercial-use reservation
• updates pyproject.toml from AGPL-3.0-only to PolyForm-Noncommercial-1.0.0
• updates release-readiness tests so CI enforces the new licensing posture across package metadata, README, and LICENSE.md

Governance intent

Foundational TRIA IP remains with Trivian Institute. Trivian Technologies receives no special ownership or licensing carve-out and would obtain commercial rights under the same Institute-governed licensing framework as other commercial users.

No Core, Runtime, schema, projection, bundle, hashing, or conformance semantics are changed.