Cardano Updates

The reward update (RUPD) admitted pools into the stake snapshot via an
epoch-addressed test (`snapshot_at(stake_epoch)`) but then read pool params
and blocks through fixed positional slots (`.go()`/`.mark()`) and unwrapped
them. These agree only when a pool's `EpochValue.epoch == current_epoch`. When
a persisted pool's snapshot lagged the `EpochState` epoch, the admission gate
passed via the `set`/`mark` slot while `go` was still `None`, causing an
obscure `Option::unwrap() on a None value` panic deep in `define_rewards`
(loading.rs:510) that unwound the worker thread and brought down the daemon.

Rather than mask the lag by switching the accessors to `snapshot_at(...)`
(which would silently drop pools lagging beyond the snapshot window and corrupt
rewards with no signal), validate the alignment invariant up front: every
stored `PoolState` must have `snapshot.epoch() == current_epoch` (ESTART
transitions all pools each boundary). A violation now returns a descriptive
`ChainError::PoolSnapshotLagging` naming the pool hash and the epoch mismatch,
which propagates cleanly through the gasket stage (no thread-panic cascade) and
omits nothing — the whole RUPD fails loud rather than computing partial data.

- add `ChainError::PoolSnapshotLagging { pool, pool_epoch, current_epoch }`
- validate every pool in `StakeSnapshot::load_globals` (checked over all pools,
  so a pool lagging out of the admission window is caught, not dropped)
- harden the `pool_params`/`pool_blocks` unwraps with descriptive messages as a
  backstop against regressing to the obscure panic
- unit tests for the alignment check

This only surfaces the lag; recovering/repairing a lagging pool and finding its
root cause (bootstrap import vs sharded boundary resume) is a follow-up.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

Reconciled hardcoded Conway proposal outcomes in hacks.rs against DBSync.

Mainnet:
- Treasury Withdrawals batch 73e171a4...#0,1,2,3,5,6 (enacted 634) -> Ratified(633)
- Treasury Withdrawal 3f0ff0d8...#0 (enacted 635) -> Ratified(634)
- Treasury Withdrawal 4206ae0b...#0 (enacted 635) -> Ratified(634)

Preprod:
- Parameter Change 3e1b4d54...#0 (enacted 289) -> Ratified(288)
- Hard Fork Initiation 79fb4bac...#0 (enacted 294) -> Ratified(293)

Preview: no changes; all enacted proposals already mapped.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>