Rebrand to Cryptographic Triangles v5.1.3

- Rename client from "Black Pharao" to "Cryptographic Triangles"
- Update CLIENT_VERSION from 4.2.1.0 to 5.1.3.0
- Update DISPLAY_VERSION from 5.0.0.0 to 5.1.3.0
- Update .pro VERSION to 5.1.3.0
- Fix RC file: copyright 2014-2026, fix OriginalFilename typo
- Update about dialog copyright to 2014-2026

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

src/version.cpp

@@ -8,7 +8,7 @@
 // Name of client reported in the 'version' message. Report the same name
 // for both trianglesd and triangles-qt, to make it harder for attackers to
 // target servers or GUI users specifically.
-const std::string CLIENT_NAME("Black Pharao");
+const std::string CLIENT_NAME("Cryptographic Triangles");
 
 // Client version number
 #define CLIENT_VERSION_SUFFIX   ""