fix(v2): enforce MAX_ANTI_SNIPE_HARD_MAX_SECS upper bound on initialize

[Santia2004]

Closes #114

Summary

• Added MAX_ANTI_SNIPE_HARD_MAX_SECS constant (30 * 24 * 60 * 60, 30 days) to prevent setting an unbounded or excessively large anti_snipe_hard_max_secs at initialization that could lead to arithmetic overflow during dispute resolution.
• Added upper bound validation check in initialize() for tholos-v2, returning Error::InvalidAntiSnipeParams if anti_snipe_hard_max_secs > MAX_ANTI_SNIPE_HARD_MAX_SECS.
• Added unit tests in test.rs to verify rejection of values above MAX_ANTI_SNIPE_HARD_MAX_SECS as well as acceptance at the exact bound.

Test plan

• Added test_initialize_rejects_anti_snipe_hard_max_over_max covering rejection of out-of-bound values.
• Added test_initialize_accepts_anti_snipe_hard_max_at_max ensuring valid boundary values initialize cleanly.
• Preserved all existing relative checks (anti_snipe_hard_max_secs >= registration_duration_secs and anti_snipe_extension_secs <= anti_snipe_hard_max_secs).