version: bump PROTOCOL_VERSION for the v1.3.0 consensus changes

doc/release-process.md requires PROTOCOL_VERSION to increase by 1 for any release
carrying a consensus change. This one does: 6d282db21 stops BLOCK_VALID_CONTEXT
overwriting the block validity level, 267e6f7ad drops the dead CBOPRET price
validation from the coinbase check, and pow.cpp is 157 lines lighter. The value
has not moved since 85c8d7f7d in March.

MIN_PEER_PROTO_VERSION stays at 2000000. It currently equals PROTOCOL_VERSION, so
raising it in step would disconnect every peer still announcing 2000000 -- which is
every user, because no DragonX release has ever been installable: the wallet's
updater pins an ed25519 key and sets kDaemonRequireSignature = true, and no release
has ever shipped a .sig. Bumping only the advertised version lets 1.3.0 nodes be
identified on the wire without partitioning the network on release day.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FU87LdsJZiZkfq1eXubpeo

src/version.h

@@ -22,7 +22,13 @@
 
 // network protocol versioning
 // DragonX 1.0.0 - bumped to separate from old HUSH/DragonX nodes with RandomX bug
-static const int PROTOCOL_VERSION = 2000000;
+// DragonX 1.3.0 - bumped for the consensus changes in this release (BLOCK_VALID_CONTEXT
+//                 no longer overwrites the validity level, the dead CBOPRET coinbase
+//                 price check is gone, and pow.cpp lost 157 lines). MIN_PEER_PROTO_VERSION
+//                 is deliberately NOT raised: it currently equals this value, and raising
+//                 it would disconnect every node still on v1.0.3 -- which is all users,
+//                 since no release has ever been installable (unsigned archives).
+static const int PROTOCOL_VERSION = 2000001;
 //! initial proto version, to be increased after version/verack negotiation
 static const int INIT_PROTO_VERSION = 209;
 //! In this version, 'getheaders' was introduced.