Initial commit: snapshot of spesmilo/electrumx 2.0.0

Unmodified source tree of upstream commit 280cb339aa158e099eb936033eecd15719770651
("Merge pull request #389 from SomberNight/202607_release_2_0",
https://github.com/spesmilo/electrumx, release 2.0.0, 3 July 2026).

All Palladium-specific changes are in the commits that follow.

tests/blocks/egulden_mainnet_1000.json

@@ -0,0 +1,26 @@
+{
+    "bits": "1e0ffff0",
+    "certified": false,
+    "chainwork": "000000000000000000000000000000000000000000000000000000003e903e90",
+    "confirmations": 1574723,
+    "difficulty": 0.000244140625,
+    "hash": "99f4bacb2876ffcd74bcbaebfc9fdb5f6fabfc2e740b5d404f7f8935fef6506f",
+    "height": 1000,
+    "identified": false,
+    "mediantime": 1395260482,
+    "merkleroot": "e665cc3f6fe0abf603c4137a5177d99236b0fa6ea78a1a718d49c6a8e4a58297",
+    "nextblockhash": "41164466777a8da56baeee3ab5522e7b64d53df6f32065abc6162ee1a1fc082d",
+    "nonce": 108593152,
+    "oeru_height": -1,
+    "previousblockhash": "4b0ad0c3f83cde7ba92b229f1de84d512ff0d744c08632cfa2a47c3fc8926f62",
+    "size": 188,
+    "strippedsize": 188,
+    "time": 1395260486,
+    "tx": [
+      "e665cc3f6fe0abf603c4137a5177d99236b0fa6ea78a1a718d49c6a8e4a58297"
+    ],
+    "version": 2,
+    "versionHex": "00000002",
+    "weight": 752,
+    "block": "02000000626f92c83f7ca4a2cf3286c044d7f02f514de81d9f222ba97bde3cf8c3d00a4b9782a5e4a8c6498d711a8aa76efab03692d977517a13c403f6abe06f3fcc65e646fc2953f0ff0f1e000079060101000000010000000000000000000000000000000000000000000000000000000000000000ffffffff0c02e8030151062f503253482fffffffff0100f90295000000002321023b98f0b6209f54dad83768a0e898c46a47bd60a8142581bc680430e37e2e025eac00000000"
+  }