Contract details lock

Contract terms are settled once the job is awarded. The screen now treats them that way.

• Locked by default past award. Contract #, value, retainage, the dates and the GC show as plain text — "$406,685", "Sep 19, 2026" — instead of open input boxes.
• Unlock when you need to. The button on the Contract Details card opens every field, the awarded GC included, for this visit. Lock it again when you're done; leaving the page locks it too.