feat: add per-pool resolution delay (#553)

[edehvictor]

Closes #553

Changes

• add delay: u64 to PoolConfig and persist the resolved value on each pool
• use per-pool delay for operator resolution, oracle resolution, system resolution, and mark_pool_ready
• keep existing callers backward-compatible by treating delay: 0 as "inherit the current global resolution delay"
• update contract test fixtures and pool config literals to include the new field
• add a regression test verifying a pool-specific delay can override the global delay

Testing

• cargo fmt
• cargo test (blocked locally: missing MSVC linker link.exe on this machine)