op/zora/mainnet: add missing hardfork timestamps and eip1559DenominatorCanyon to genesis.json

Fixes op-reth stuck at genesis (block 0) due to missing Shanghai/Canyon+ forks.
op-node feeds current-head payloads with withdrawals but op-reth rejects them
as 'withdrawals pre-Shanghai' without these timestamps.

Added hardfork timestamps:
- shanghaiTime: 1704992401 (activates Shanghai/withdrawals)
- canyonTime: 1704992401 (activates Canyon)
- deltaTime: 1708560000
- ecotoneTime: 1710374401
- fjordTime: 1720627201
- graniteTime: 1726070401
- holoceneTime: 1736445601
- isthmusTime: 1746806401
- jovianTime: 1764691201
- karstTime: 1783526401

Added optimism.eip1559DenominatorCanyon: 250

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

op/zora/mainnet/genesis.json

@@ -21,8 +21,19 @@
     "terminalTotalDifficultyPassed": true,
     "optimism": {
       "eip1559Elasticity": 6,
-      "eip1559Denominator": 50
-    }
+      "eip1559Denominator": 50,
+      "eip1559DenominatorCanyon": 250
+    },
+    "shanghaiTime": 1704992401,
+    "canyonTime": 1704992401,
+    "deltaTime": 1708560000,
+    "ecotoneTime": 1710374401,
+    "fjordTime": 1720627201,
+    "graniteTime": 1726070401,
+    "holoceneTime": 1736445601,
+    "isthmusTime": 1746806401,
+    "jovianTime": 1764691201,
+    "karstTime": 1783526401
   },
   "nonce": "0x0",
   "timestamp": "0x6488e7cf",