feat: initial commit of Claude Code configuration

Add comprehensive Claude Code setup including:
- Custom coding rules (Go, Git, Testing, Security, Patterns)
- 24 installed plugins (Voltagent, Workflows, Skills)
- Cross-platform installers (bash, PowerShell)
- Complete documentation

This configuration provides the same powerful development
environment across any Claude Code installation.

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

rules/testing.md

@@ -0,0 +1,25 @@
+# Go Testing
+
+> This file extends [common/testing.md](../common/testing.md) with Go specific content.
+
+## Framework
+
+Use the standard `go test` with **table-driven tests**.
+
+## Race Detection
+
+Always run with the `-race` flag:
+
+```bash
+go test -race ./...
+```
+
+## Coverage
+
+```bash
+go test -cover ./...
+```
+
+## Reference
+
+See skill: `golang-testing` for detailed Go testing patterns and helpers.