refactor: drop from __future__ import annotations in Pydantic-defining files (leanEthereum#759)

CLAUDE.md rule R1 bans the lazy-annotations import in files that
define Pydantic Container or SSZModel classes; lazy-string
annotations break Pydantic's forward-reference resolution. Six
audit-flagged files still carried it.

state/types.py needed a small adjustment after the drop: three
classmethod-like helpers on JustifiedSlots returned the class by
name (-> JustifiedSlots). Without future annotations the bare name
is undefined at signature evaluation, so they switch to typing.Self
which reads cleaner anyway for self-referential factories.

R2 (Store = LstarStore alias) is intentionally left alone. The
alias is the public generic name that lets subspecs (sync, api,
node, ...) reference "the current fork's Store" without importing
forks.lstar.*. Removing it would couple subspecs to the concrete
fork, defeating the multi-fork architecture (leanEthereum#686).

R3 (QUIC random peer-id anti-pattern) needs real libp2p TLS
extension parsing and belongs in its own PR.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: tcoratger

src/lean_spec/forks/lstar/containers/attestation/attestation.py

@@ -11,8 +11,6 @@
 Attestations can be aggregated by common data to save space and bandwidth.
 """
 
-from __future__ import annotations
-
 from lean_spec.subspecs.xmss.aggregation import TypeOneMultiSignature
 from lean_spec.subspecs.xmss.containers import Signature
 from lean_spec.types import AggregationBits, Checkpoint, Container, Slot, ValidatorIndex

src/lean_spec/forks/lstar/containers/block/types.py

@@ -1,7 +1,5 @@
 """Block-specific SSZ types for the Lean Ethereum consensus specification."""
 
-from __future__ import annotations
-
 from lean_spec.subspecs.chain.config import VALIDATOR_REGISTRY_LIMIT
 from lean_spec.types import SSZList
 

src/lean_spec/forks/lstar/containers/state/state.py

@@ -1,7 +1,5 @@
 """State Container for the Lean Ethereum consensus specification."""
 
-from __future__ import annotations
-
 from lean_spec.forks.lstar.containers.block import BlockHeader
 from lean_spec.forks.lstar.containers.config import Config
 from lean_spec.forks.lstar.containers.state.types import (

src/lean_spec/forks/lstar/containers/state/types.py

@@ -1,6 +1,6 @@
 """State-specific SSZ types for the Lean Ethereum consensus specification."""
 
-from __future__ import annotations
+from typing import Self
 
 from lean_spec.subspecs.chain.config import HISTORICAL_ROOTS_LIMIT, VALIDATOR_REGISTRY_LIMIT
 from lean_spec.types import Boolean, Bytes32, Slot, SSZList
@@ -67,7 +67,7 @@ def with_justified(
         finalized_slot: Slot,
         target_slot: Slot,
         value: Boolean,
-    ) -> JustifiedSlots:
+    ) -> Self:
         """
         Return a new bitfield with the justification status updated.
 
@@ -112,7 +112,7 @@ def with_justified(
 
         return self.model_copy(update={"data": new_data})
 
-    def extend_to_slot(self, finalized_slot: Slot, target_slot: Slot) -> JustifiedSlots:
+    def extend_to_slot(self, finalized_slot: Slot, target_slot: Slot) -> Self:
         """
         Extend the tracking capacity to cover a new target slot.
 
@@ -147,7 +147,7 @@ def extend_to_slot(self, finalized_slot: Slot, target_slot: Slot) -> JustifiedSl
         # We extend the existing data with False values to bridge the gap.
         return self.model_copy(update={"data": list(self.data) + [Boolean(False)] * gap_size})
 
-    def shift_window(self, delta: int) -> JustifiedSlots:
+    def shift_window(self, delta: int) -> Self:
         """
         Advance the tracking window by dropping slots that became finalized.
 

src/lean_spec/forks/lstar/containers/validator.py

@@ -1,7 +1,5 @@
 """Validator container for the Lean Ethereum consensus specification."""
 
-from __future__ import annotations
-
 from lean_spec.subspecs.chain.config import VALIDATOR_REGISTRY_LIMIT
 from lean_spec.subspecs.xmss.containers import PublicKey
 from lean_spec.types import Bytes52, Container, SSZList, ValidatorIndex

src/lean_spec/subspecs/xmss/rand.py

@@ -1,7 +1,5 @@
 """Random data generator for the XMSS signature scheme."""
 
-from __future__ import annotations
-
 import secrets
 
 from lean_spec.types import StrictBaseModel