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_user.go

@@ -0,0 +1,86 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"time"
+)
+
+func (c *KVSClient) handleUserList(args []string) {
+	// Note: Backend doesn't have a list-all endpoint, this would need to be added
+	fmt.Println(yellow("User listing not implemented in backend API"))
+}
+
+func (c *KVSClient) handleUserGet(args []string) {
+	if len(args) < 1 {
+		fmt.Println(red("Usage: user get <uuid>"))
+		return
+	}
+
+	respBody, status, err := c.doRequest("GET", "/api/users/"+args[0], nil)
+	if err != nil {
+		fmt.Println(red("Error:"), err)
+		return
+	}
+
+	if status == 404 {
+		fmt.Println(yellow("User not found"))
+		return
+	}
+
+	if status != 200 {
+		fmt.Println(red("Error:"), string(respBody))
+		return
+	}
+
+	var user User
+	if err := json.Unmarshal(respBody, &user); err != nil {
+		fmt.Println(red("Error parsing response:"), err)
+		return
+	}
+
+	fmt.Println(cyan("User Details:"))
+	fmt.Printf("  UUID:          %s\n", user.UUID)
+	fmt.Printf("  Nickname Hash: %s\n", user.NicknameHash)
+	fmt.Printf("  Groups:        %v\n", user.Groups)
+	fmt.Printf("  Created:       %s\n", time.Unix(user.CreatedAt, 0).Format(time.RFC3339))
+	fmt.Printf("  Updated:       %s\n", time.Unix(user.UpdatedAt, 0).Format(time.RFC3339))
+}
+
+func (c *KVSClient) handleUserCreate(args []string) {
+	if len(args) < 1 {
+		fmt.Println(red("Usage: user create <nickname>"))
+		return
+	}
+
+	// The request body requires a JSON object like {"nickname": "..."}
+	requestPayload := map[string]string{
+		"nickname": args[0],
+	}
+
+	respBody, status, err := c.doRequest("POST", "/api/users", requestPayload)
+	if err != nil {
+		fmt.Println(red("Error:"), err)
+		return
+	}
+
+	// The backend returns 200 OK on success
+	if status != http.StatusOK {
+		fmt.Printf(red("Error creating user (status %d):\n"), status)
+		fmt.Println(string(respBody))
+		return
+	}
+
+	// Parse the successful response to get the new user's UUID
+	var response struct {
+		UUID string `json:"uuid"`
+	}
+	if err := json.Unmarshal(respBody, &response); err != nil {
+		fmt.Println(red("Error parsing successful response:"), err)
+		return
+	}
+
+	fmt.Println(green("User created successfully"))
+	fmt.Println(cyan("UUID:"), response.UUID)
+}