[Bug][ML] ManagedLedger.terminate() can race with ledger rollover and make a terminated ledger writable again

### Describe the bug

`ManagedLedger.terminate()` can race with ledger rollover and allow a managed ledger that has already entered `Terminated` state to be moved back to `LedgerOpened` by a delayed rollover callback.

### Problem

`ManagedLedger.terminate()` seals the managed ledger at the current BookKeeper committed boundary. After termination, no new entries should be accepted and the managed ledger should not become writable again.

The key invariant should be:

> Any add operation that is acknowledged successfully to the caller must have a position less than or equal to the final `terminatedPosition`.

However, there is a race between `terminate()` and ledger rollover:

1. An add fills the current ledger and triggers rollover.
2. The managed ledger moves into `ClosingLedger` / `CreatingLedger`.
3. `terminate()` runs before the rollover create/switch callback finishes and marks the managed ledger as `Terminated`.
4. The delayed `createComplete()` or `updateLedgersIdsComplete()` callback resumes the old rollover flow.
5. The callback can set the state back to `LedgerOpened`, making a terminated managed ledger writable again.

### Expected behavior

After `terminate()` takes ownership of the managed ledger state:

- `Terminated` should remain the final write state.
- Queued adds that were not sent to BookKeeper should fail with `ManagedLedgerTerminatedException`.
- In-flight adds already sent to BookKeeper should only succeed if they are included in the final LAC / `terminatedPosition`.
- Late ledger create or ledger switch callbacks should not reopen the managed ledger.
- Termination should not create or switch to another writable ledger for pending writes.

### Actual behavior

A delayed rollover callback can continue the normal ledger-switch path after termination and move the managed ledger back to `LedgerOpened`. This can break termination semantics, incorrectly handle pending writes as normal rollover writes, or leave add callbacks hanging when BookKeeper close drains writes that were not included in the final LAC.

### Verification / reproducer

The scenario is covered by tests added in #25795:

- `terminateDuringLedgerSwitchKeepsTerminatedState`
- `terminatePositionIncludesAddAlreadyAckedByBookKeeper`
- `terminateFailsInflightAddDrainedByLedgerClose`
- `ledgerSwitchCompletionDoesNotReopenTerminatedLedger`

Local verification from the related PR:

```bash
./gradlew :managed-ledger:test --tests org.apache.bookkeeper.mledger.impl.ManagedLedgerTerminationTest
./gradlew :managed-ledger:checkstyleMain :managed-ledger:checkstyleTest
```

### Affected area

Managed ledger termination and ledger rollover state transitions.

### Related PR

#25795

Start with the managed-ledger termination and rollover state transitions, then run ManagedLedgerTerminationTest in the managed-ledger module. Review terminateDuringLedgerSwitchKeepsTerminatedState, terminatePositionIncludesAddAlreadyAckedByBookKeeper, terminateFailsInflightAddDrainedByLedgerClose, and ledgerSwitchCompletionDoesNotReopenTerminatedLedger; done means termination remains final, pending adds receive the expected result, and the listed tests plus checkstyle pass.

Written by the indexing model from the issue text.