Add RPC commands, systemd service, and operational docs

New RPC commands:
- addnode: add/remove/onetry .onion peers at runtime
- disconnectnode: immediately drop a peer connection
- getchaintips: diagnose chain forks and orphan branches
- invalidateblock: rewind chain past a bad block
- reconsiderblock: re-activate a previously invalidated block

Also includes:
- systemd service files for Linux deployment
- Bootstrap/snapshot guide for OpenClaw nodes
- Upgrade notes from 2026-04-14

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/trianglesrpc.cpp

@@ -248,6 +248,8 @@ static const CRPCCommand vRPCCommands[] =
     { "getblockcount",          &getblockcount,          true,   false },
     { "getconnectioncount",     &getconnectioncount,     true,   false },
     { "getpeerinfo",            &getpeerinfo,            true,   false },
+    { "addnode",                &addnode,                true,   false },
+    { "disconnectnode",         &disconnectnode,         true,   false },
     { "getdifficulty",          &getdifficulty,          true,   false },
     { "getblockheader",         &getblockheader,         true,   false },
     { "getblockchaininfo",      &getblockchaininfo,      true,   false },
@@ -312,6 +314,9 @@ static const CRPCCommand vRPCCommands[] =
     { "signrawtransaction",     &signrawtransaction,     false,  false },
     { "sendrawtransaction",     &sendrawtransaction,     false,  false },
     { "getcheckpoint",          &getcheckpoint,          true,   false },
+    { "getchaintips",           &getchaintips,           true,   false },
+    { "invalidateblock",        &invalidateblock,        false,  false },
+    { "reconsiderblock",        &reconsiderblock,        false,  false },
     { "reservebalance",         &reservebalance,         false,  true},
     { "checkwallet",            &checkwallet,            false,  true},
     { "repairwallet",           &repairwallet,           false,  true},