refactor(repo): consolidate openflare-server to root and move subprojects to internal/apps

- Merge all files inside openflare-server to the repository root directory.
- Relocate agent, relay, and flared subprojects from internal/ to internal/apps/.
- Combine docker-compose files and update build context paths to root.
- Update GitHub workflows and Dockerfiles to refer to new directories and package names.
- Rewrite Go package imports across all files.
- Resolve database renew test race condition and clean up docs.

internal/apps/flared/httpclient/client.go

@@ -0,0 +1,143 @@
+package httpclient
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"io"
+	"log/slog"
+	"net/http"
+	"strings"
+	"time"
+
+	service "github.com/Rain-kl/Wavelet/pkg/protocol"
+)
+
+type APIResponse[T any] struct {
+	ErrorMsg string `json:"error_msg"`
+	Data     T      `json:"data"`
+}
+
+type Client struct {
+	baseURL    string
+	token      string
+	httpClient *http.Client
+}
+
+func New(baseURL string, token string, timeout time.Duration) *Client {
+	return &Client{
+		baseURL: strings.TrimRight(baseURL, "/"),
+		token:   token,
+		httpClient: &http.Client{
+			Timeout: timeout,
+		},
+	}
+}
+
+func (c *Client) Heartbeat(ctx context.Context, payload service.FlaredHeartbeatPayload) (*service.FlaredHeartbeatResponse, error) {
+	resp := APIResponse[service.FlaredHeartbeatResponse]{}
+	if err := c.postJSON(ctx, "/api/v1/tunnel/heartbeat", payload, &resp); err != nil {
+		return nil, err
+	}
+	if err := apiError(resp.ErrorMsg); err != nil {
+		return nil, err
+	}
+	return &resp.Data, nil
+}
+
+func (c *Client) GetActiveConfig(ctx context.Context) (*service.FlaredTunnelConfigResponse, error) {
+	resp := APIResponse[service.FlaredTunnelConfigResponse]{}
+	if err := c.getJSON(ctx, "/api/v1/tunnel/config/active", &resp); err != nil {
+		return nil, err
+	}
+	if err := apiError(resp.ErrorMsg); err != nil {
+		return nil, err
+	}
+	return &resp.Data, nil
+}
+
+func (c *Client) ReportApplyLog(ctx context.Context, payload service.ApplyLogPayload) error {
+	resp := APIResponse[any]{}
+	if err := c.postJSON(ctx, "/api/v1/tunnel/apply-log", payload, &resp); err != nil {
+		return err
+	}
+	return apiError(resp.ErrorMsg)
+}
+
+func (c *Client) SetToken(token string) {
+	c.token = strings.TrimSpace(token)
+	slog.Debug("http client token updated")
+}
+
+func (c *Client) getJSON(ctx context.Context, path string, target any) error {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, c.baseURL+path, nil)
+	if err != nil {
+		return err
+	}
+	req.Header.Set("X-Tunnel-Token", c.token)
+	return c.do(req, target)
+}
+
+func (c *Client) postJSON(ctx context.Context, path string, body any, target any) error {
+	data, err := json.Marshal(body)
+	if err != nil {
+		return err
+	}
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, c.baseURL+path, bytes.NewReader(data))
+	if err != nil {
+		return err
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("X-Tunnel-Token", c.token)
+	return c.do(req, target)
+}
+
+func (c *Client) do(req *http.Request, target any) error {
+	res, err := c.httpClient.Do(req)
+	if err != nil {
+		slog.Error("http request failed", "method", req.Method, "path", req.URL.Path, "error", err)
+		return err
+	}
+	defer func(Body io.ReadCloser) {
+		err := Body.Close()
+		if err != nil {
+			slog.Error("failed to close response body", "error", err)
+		}
+	}(res.Body)
+
+	body, err := io.ReadAll(res.Body)
+	if err != nil {
+		slog.Error("http response read failed", "method", req.Method, "path", req.URL.Path, "error", err)
+		return err
+	}
+	if res.StatusCode != http.StatusOK {
+		slog.Warn("http request returned non-200", "method", req.Method, "path", req.URL.Path, "status", res.Status)
+		return readBodyError(body, res.Status)
+	}
+	if target == nil {
+		return nil
+	}
+	if err = json.Unmarshal(body, target); err != nil {
+		slog.Error("http response decode failed", "method", req.Method, "path", req.URL.Path, "error", err)
+		return err
+	}
+	return nil
+}
+
+func apiError(msg string) error {
+	if strings.TrimSpace(msg) == "" {
+		return nil
+	}
+	return errors.New(msg)
+}
+
+func readBodyError(body []byte, fallback string) error {
+	var errBody struct {
+		ErrorMsg string `json:"error_msg"`
+	}
+	if err := json.Unmarshal(body, &errBody); err == nil && strings.TrimSpace(errBody.ErrorMsg) != "" {
+		return errors.New(errBody.ErrorMsg)
+	}
+	return errors.New(fallback)
+}