[SrMessiSOL]

What changed

• add a canonical ownership PDA keyed by planet
• create registries for new homeworlds and colonies
• migrate existing planets through the vault-signed owner-index sync
• require and update canonical ownership during direct transfers and market purchases
• validate canonical ownership before creating planet listings

Root cause

Owner indexes were keyed by wallet and slot, while PlanetState did not identify the current owner's canonical slot. Transfers could therefore leave stale indexes and the program could not prove which index must be deactivated.

Impact

Planet transfers now atomically deactivate the exact previous owner index and move the canonical registry to the buyer. Existing planet state accounts are unchanged and require only a small one-time registry PDA migration.

Validation

• cargo test --workspace --lib --locked: 51 passed
• git diff --check