feat: implement core CLI packages and Phase 3 commands

- config: resolve binary dir, load/save .hf-config.json
- mode: detect padded-cell vs manual mode via pass_mgr
- client: HTTP client wrapper with auth header support
- passmgr: pass_mgr integration (get-secret, set, generate)
- output: human-readable + JSON output formatting with tables
- help: help and help-brief renderer for groups/commands
- commands: version, health, config (--url, --acc-mgr-token, show)
- auth: token resolution helper (padded-cell auto / manual explicit)
- main: command dispatcher with --json global flag support
- README: updated with current package layout and status

internal/client/client.go

@@ -0,0 +1,105 @@
+// Package client provides the HTTP client wrapper for HarborForge API calls.
+package client
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+)
+
+// Client is a simple HarborForge API client.
+type Client struct {
+	BaseURL    string
+	Token      string
+	HTTPClient *http.Client
+}
+
+// New creates a Client with the given base URL and optional auth token.
+func New(baseURL, token string) *Client {
+	return &Client{
+		BaseURL: strings.TrimRight(baseURL, "/"),
+		Token:   token,
+		HTTPClient: &http.Client{
+			Timeout: 30 * time.Second,
+		},
+	}
+}
+
+// RequestError represents a non-2xx HTTP response.
+type RequestError struct {
+	StatusCode int
+	Body       string
+}
+
+func (e *RequestError) Error() string {
+	return fmt.Sprintf("HTTP %d: %s", e.StatusCode, e.Body)
+}
+
+// Do executes an HTTP request and returns the response body bytes.
+func (c *Client) Do(method, path string, body io.Reader) ([]byte, error) {
+	url := c.BaseURL + path
+	req, err := http.NewRequest(method, url, body)
+	if err != nil {
+		return nil, fmt.Errorf("cannot create request: %w", err)
+	}
+	if c.Token != "" {
+		req.Header.Set("Authorization", "Bearer "+c.Token)
+	}
+	if body != nil {
+		req.Header.Set("Content-Type", "application/json")
+	}
+	resp, err := c.HTTPClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("request failed: %w", err)
+	}
+	defer resp.Body.Close()
+	data, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("cannot read response: %w", err)
+	}
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		return nil, &RequestError{StatusCode: resp.StatusCode, Body: string(data)}
+	}
+	return data, nil
+}
+
+// Get performs a GET request.
+func (c *Client) Get(path string) ([]byte, error) {
+	return c.Do("GET", path, nil)
+}
+
+// Post performs a POST request with a JSON body.
+func (c *Client) Post(path string, body io.Reader) ([]byte, error) {
+	return c.Do("POST", path, body)
+}
+
+// Put performs a PUT request with a JSON body.
+func (c *Client) Put(path string, body io.Reader) ([]byte, error) {
+	return c.Do("PUT", path, body)
+}
+
+// Patch performs a PATCH request with a JSON body.
+func (c *Client) Patch(path string, body io.Reader) ([]byte, error) {
+	return c.Do("PATCH", path, body)
+}
+
+// Delete performs a DELETE request.
+func (c *Client) Delete(path string) ([]byte, error) {
+	return c.Do("DELETE", path, nil)
+}
+
+// Health checks the API health endpoint and returns the response.
+func (c *Client) Health() (map[string]interface{}, error) {
+	data, err := c.Get("/api/health/")
+	if err != nil {
+		return nil, err
+	}
+	var result map[string]interface{}
+	if err := json.Unmarshal(data, &result); err != nil {
+		return nil, fmt.Errorf("cannot parse health response: %w", err)
+	}
+	return result, nil
+}