Update fault fees and recovery mechanics per FIP-0002

[lanzafame]

This commit updates the Filecoin specification to reflect the changes introduced by FIP-0002 (Free Faults on Newly Faulted Sectors of a Missed WindowPoSt). The key changes include:

1. Updated Sector Fault Fee from 2.14 to 3.51 days of expected block reward
2. Added DeclaredFaultProjectionPeriod constant (3.51 days)
3. Removed Sector Fault Detection Fee references
4. Updated fault detection behavior:
   • 100% healthy partitions incur no immediate fee when missing WindowPoSt
   • Only already faulty/recovering sectors are charged
5. Removed recovery fees - successful recovery no longer incurs penalties
6. Updated skipped fault handling to defer penalties to next proving period

These changes better accommodate operational failures while maintaining incentives for reliable storage.

Reference: FIP-0002