refactor: split monolithic main.go into modular structure

Refactored 800+ line main.go into clean, domain-separated files:
- main.go (96 lines) - Entry point and command router only
- types.go - Type definitions and data structures
- client.go - HTTP client and request handling
- cmd_kv.go - Key-value operations (get/put/delete)
- cmd_meta.go - Resource metadata commands
- cmd_user.go - User management commands
- cmd_profile.go - Profile management
- cmd_cluster.go - Cluster operations (members/health)
- cmd_system.go - System commands (connect/auth/help)
- utils.go - Shared utilities (parsing, colors, completion)

No functional changes, pure reorganization for maintainability.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

cmd_profile.go

@@ -0,0 +1,69 @@
+package main
+
+import "fmt"
+
+func (c *KVSClient) handleProfile(args []string) {
+	if len(args) == 0 {
+		// List profiles
+		if len(c.profiles) == 0 {
+			fmt.Println(yellow("No profiles configured"))
+			return
+		}
+		fmt.Println(cyan("Available profiles:"))
+		for name, profile := range c.profiles {
+			marker := " "
+			if name == c.activeProfile {
+				marker = "*"
+			}
+			fmt.Printf("%s %s (user: %s, url: %s)\n", marker, name, profile.UserUUID, profile.BaseURL)
+		}
+		return
+	}
+
+	subCmd := args[0]
+	switch subCmd {
+	case "add":
+		if len(args) < 4 {
+			fmt.Println(red("Usage: profile add <name> <token> <user-uuid> [base-url]"))
+			return
+		}
+		baseURL := c.baseURL
+		if len(args) >= 5 {
+			baseURL = args[4]
+		}
+		c.profiles[args[1]] = Profile{
+			Name:     args[1],
+			Token:    args[2],
+			UserUUID: args[3],
+			BaseURL:  baseURL,
+		}
+		fmt.Println(green("Profile added:"), args[1])
+
+	case "use":
+		if len(args) < 2 {
+			fmt.Println(red("Usage: profile use <name>"))
+			return
+		}
+		profile, ok := c.profiles[args[1]]
+		if !ok {
+			fmt.Println(red("Profile not found:"), args[1])
+			return
+		}
+		c.currentToken = profile.Token
+		c.currentUser = profile.UserUUID
+		c.baseURL = profile.BaseURL
+		c.activeProfile = args[1]
+		fmt.Println(green("Switched to profile:"), args[1])
+
+	case "remove":
+		if len(args) < 2 {
+			fmt.Println(red("Usage: profile remove <name>"))
+			return
+		}
+		delete(c.profiles, args[1])
+		if c.activeProfile == args[1] {
+			c.activeProfile = ""
+		}
+		fmt.Println(green("Profile removed:"), args[1])
+	}
+}