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/security.md

@@ -0,0 +1,28 @@
+# Go Security
+
+> This file extends [common/security.md](../common/security.md) with Go specific content.
+
+## Secret Management
+
+```go
+apiKey := os.Getenv("OPENAI_API_KEY")
+if apiKey == "" {
+    log.Fatal("OPENAI_API_KEY not configured")
+}
+```
+
+## Security Scanning
+
+- Use **gosec** for static security analysis:
+  ```bash
+  gosec ./...
+  ```
+
+## Context & Timeouts
+
+Always use `context.Context` for timeout control:
+
+```go
+ctx, cancel := context.WithTimeout(ctx, 5*time.Second)
+defer cancel()
+```