fix: Agent.from_dict no status validation — allows invalid states via deserialization

[branben]

What to build

Agent.from_dict does status=data.get('status', 'idle') but never validates against allowed values ("idle", "working", "sleeping"). A corrupted JSON file creates an Agent that violates the state machine contract.

Add: if status not in VALID_STATUSES: status = "idle".

Acceptance criteria

• Invalid status values default to "idle"
• Tests verify corrupt JSON is handled gracefully

Blocked by

None - can start immediately

Parent

Tracks the campus framework v1 code review: #27

[branben]

Closing: code referenced in this issue no longer exists (campus framework removed) or fix already applied.