Initial implementation: host lifecycle + PXE + admin dashboard

Go service for Proxmox homelab cluster provisioning. Handles PXE boot,
Proxmox autoinstall (answer file generation), cluster join via SSH,
and Infrastructure API registration.

- Host state machine (registered → pxe_ready → installing → ready)
- dnsmasq supervisor with MAC-based allowlist
- iPXE script and Proxmox answer file generation
- First-boot phone-home → cluster join → infra registration
- Operation locking with expiry (409 on conflict)
- SSE event hub for real-time dashboard updates
- Admin dashboard (host grid, detail, registration form)
- Config-driven server types with hot-reload
- Docker deployment (multi-stage fat image)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/infra/client.go

@@ -0,0 +1,92 @@
+package infra
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"time"
+)
+
+type Client struct {
+	BaseURL    string
+	HTTPClient *http.Client
+}
+
+func NewClient(baseURL string, timeout time.Duration) *Client {
+	return &Client{
+		BaseURL:    baseURL,
+		HTTPClient: &http.Client{Timeout: timeout},
+	}
+}
+
+type CreateHostRequest struct {
+	HardwareID   string `json:"hardware_id"`
+	Hostname     string `json:"hostname"`
+	AssetID      string `json:"asset_id"`
+	RoomID       int    `json:"room_id"`
+	ServerTypeID int    `json:"server_type_id"`
+}
+
+type CreateHostResponse struct {
+	ID int64 `json:"id"`
+}
+
+func (c *Client) CreateHost(ctx context.Context, req CreateHostRequest) (int64, error) {
+	body, err := json.Marshal(req)
+	if err != nil {
+		return 0, err
+	}
+	httpReq, err := http.NewRequestWithContext(ctx, http.MethodPost, c.BaseURL+"/api/hosts", bytes.NewReader(body))
+	if err != nil {
+		return 0, err
+	}
+	httpReq.Header.Set("Content-Type", "application/json")
+
+	resp, err := c.HTTPClient.Do(httpReq)
+	if err != nil {
+		return 0, fmt.Errorf("infra: create host: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusCreated {
+		return 0, fmt.Errorf("infra: create host: status %d", resp.StatusCode)
+	}
+
+	var result CreateHostResponse
+	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+		return 0, fmt.Errorf("infra: decode response: %w", err)
+	}
+	return result.ID, nil
+}
+
+type CreateInterfaceRequest struct {
+	HostID     int    `json:"host_id"`
+	Name       string `json:"name"`
+	MACAddress string `json:"mac_address"`
+	IPAddress  string `json:"ip_address"`
+}
+
+func (c *Client) CreateInterface(ctx context.Context, req CreateInterfaceRequest) error {
+	body, err := json.Marshal(req)
+	if err != nil {
+		return err
+	}
+	httpReq, err := http.NewRequestWithContext(ctx, http.MethodPost, c.BaseURL+"/api/interfaces", bytes.NewReader(body))
+	if err != nil {
+		return err
+	}
+	httpReq.Header.Set("Content-Type", "application/json")
+
+	resp, err := c.HTTPClient.Do(httpReq)
+	if err != nil {
+		return fmt.Errorf("infra: create interface: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusCreated {
+		return fmt.Errorf("infra: create interface: status %d", resp.StatusCode)
+	}
+	return nil
+}