feat(specs): add bpo1 fork

Author: SamWilsn

src/ethereum/__init__.py

@@ -21,7 +21,7 @@
 
 import sys
 
-__version__ = "2.18.0"
+__version__ = "2.19.0"
 
 #
 #  Ensure we can reach 1024 frames of recursion

src/ethereum/forks/bpo1/__init__.py

@@ -0,0 +1,23 @@
+"""
+The first blob parameter only (BPO) fork, BPO1, includes only changes to the
+blob fee schedule.
+
+### Changes
+
+- [EIP-7892: Blob Parameter Only Hardforks][EIP-7892]
+
+### Upgrade Schedule
+
+| Network | Timestamp    | Date & Time (UTC)       | Fork Hash    | Beacon Chain Epoch |
+|---------|--------------|-------------------------|--------------|--------------------|
+| Holesky | `1759800000` | 2025-10-07 01:20:00     | `0xa280a45c` | `166400`           |
+| Sepolia | `1761017184` | 2025-10-21 03:26:24     | `0x56078a1e` | `274176`           |
+| Hoodi   | `1762365720` | 2025-11-05 18:02:00     | `0x3893353e` |  `52480`           |
+| Mainnet | `1765290071` | 2025-12-09 14:21:11     | `0xcba2a1c0` | `412672`           |
+
+[EIP-7892]: https://eips.ethereum.org/EIPS/eip-7892
+"""  # noqa: E501
+
+from ethereum.fork_criteria import ByTimestamp, ForkCriteria
+
+FORK_CRITERIA: ForkCriteria = ByTimestamp(1765290071)