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>

client.go

@@ -0,0 +1,61 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"io"
+	"net/http"
+	"time"
+)
+
+// KVSClient maintains the connection state and configuration
+type KVSClient struct {
+	baseURL       string
+	currentToken  string
+	currentUser   string
+	httpClient    *http.Client
+	profiles      map[string]Profile
+	activeProfile string
+}
+
+// NewKVSClient creates a new KVS client instance
+func NewKVSClient(baseURL string) *KVSClient {
+	return &KVSClient{
+		baseURL: baseURL,
+		httpClient: &http.Client{
+			Timeout: 30 * time.Second,
+		},
+		profiles: make(map[string]Profile),
+	}
+}
+
+// doRequest performs an HTTP request with JSON body and auth headers
+func (c *KVSClient) doRequest(method, path string, body interface{}) ([]byte, int, error) {
+	var reqBody io.Reader
+	if body != nil {
+		jsonData, err := json.Marshal(body)
+		if err != nil {
+			return nil, 0, err
+		}
+		reqBody = bytes.NewBuffer(jsonData)
+	}
+
+	req, err := http.NewRequest(method, c.baseURL+path, reqBody)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+	if c.currentToken != "" {
+		req.Header.Set("Authorization", "Bearer "+c.currentToken)
+	}
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return nil, 0, err
+	}
+	defer resp.Body.Close()
+
+	respBody, err := io.ReadAll(resp.Body)
+	return respBody, resp.StatusCode, err
+}