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/store/hosts.go

@@ -0,0 +1,126 @@
+package store
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"strings"
+	"time"
+
+	"provisioning/internal/model"
+)
+
+type Hosts struct {
+	DB *sql.DB
+}
+
+const hostColumns = `id, hostname, mac, server_type, state, ip_address, hardware_id, infra_host_id, notes, created_at, updated_at`
+
+func scanHost(row interface{ Scan(dest ...any) error }, h *model.Host) error {
+	var ip, hwID sql.NullString
+	var infraID sql.NullInt64
+	var createdAt, updatedAt string
+	if err := row.Scan(&h.ID, &h.Hostname, &h.MAC, &h.ServerType, &h.State,
+		&ip, &hwID, &infraID, &h.Notes, &createdAt, &updatedAt); err != nil {
+		return err
+	}
+	h.IPAddress = ip.String
+	h.HardwareID = hwID.String
+	if infraID.Valid {
+		h.InfraHostID = infraID.Int64
+	}
+	h.CreatedAt, _ = time.Parse(time.RFC3339, createdAt)
+	h.UpdatedAt, _ = time.Parse(time.RFC3339, updatedAt)
+	return nil
+}
+
+func (s *Hosts) Create(ctx context.Context, h model.Host) (int64, error) {
+	h.MAC = normalizeMAC(h.MAC)
+	res, err := s.DB.ExecContext(ctx, `
+		INSERT INTO hosts(hostname, mac, server_type, notes)
+		VALUES(?,?,?,?)
+	`, h.Hostname, h.MAC, h.ServerType, h.Notes)
+	if err != nil {
+		return 0, fmt.Errorf("insert host: %w", err)
+	}
+	return res.LastInsertId()
+}
+
+func (s *Hosts) List(ctx context.Context) ([]model.Host, error) {
+	rows, err := s.DB.QueryContext(ctx, `SELECT `+hostColumns+` FROM hosts ORDER BY hostname COLLATE NOCASE`)
+	if err != nil {
+		return nil, fmt.Errorf("list hosts: %w", err)
+	}
+	defer rows.Close()
+	var out []model.Host
+	for rows.Next() {
+		var h model.Host
+		if err := scanHost(rows, &h); err != nil {
+			return nil, fmt.Errorf("scan host: %w", err)
+		}
+		out = append(out, h)
+	}
+	return out, rows.Err()
+}
+
+func (s *Hosts) Get(ctx context.Context, id int64) (*model.Host, error) {
+	row := s.DB.QueryRowContext(ctx, `SELECT `+hostColumns+` FROM hosts WHERE id = ?`, id)
+	var h model.Host
+	if err := scanHost(row, &h); err != nil {
+		if err == sql.ErrNoRows {
+			return nil, ErrNotFound
+		}
+		return nil, fmt.Errorf("get host: %w", err)
+	}
+	return &h, nil
+}
+
+func (s *Hosts) GetByMAC(ctx context.Context, mac string) (*model.Host, error) {
+	row := s.DB.QueryRowContext(ctx, `SELECT `+hostColumns+` FROM hosts WHERE mac = ?`, normalizeMAC(mac))
+	var h model.Host
+	if err := scanHost(row, &h); err != nil {
+		if err == sql.ErrNoRows {
+			return nil, ErrNotFound
+		}
+		return nil, fmt.Errorf("get host by mac: %w", err)
+	}
+	return &h, nil
+}
+
+func (s *Hosts) UpdateState(ctx context.Context, id int64, state model.HostState) error {
+	res, err := s.DB.ExecContext(ctx, `UPDATE hosts SET state = ?, updated_at = strftime('%Y-%m-%dT%H:%M:%SZ','now') WHERE id = ?`, state, id)
+	if err != nil {
+		return fmt.Errorf("update host state: %w", err)
+	}
+	n, _ := res.RowsAffected()
+	if n == 0 {
+		return ErrNotFound
+	}
+	return nil
+}
+
+func (s *Hosts) UpdateIP(ctx context.Context, id int64, ip string, hardwareID string) error {
+	_, err := s.DB.ExecContext(ctx, `UPDATE hosts SET ip_address = ?, hardware_id = ?, updated_at = strftime('%Y-%m-%dT%H:%M:%SZ','now') WHERE id = ?`, ip, hardwareID, id)
+	return err
+}
+
+func (s *Hosts) UpdateInfraID(ctx context.Context, id int64, infraHostID int64) error {
+	_, err := s.DB.ExecContext(ctx, `UPDATE hosts SET infra_host_id = ?, updated_at = strftime('%Y-%m-%dT%H:%M:%SZ','now') WHERE id = ?`, infraHostID, id)
+	return err
+}
+
+func (s *Hosts) Delete(ctx context.Context, id int64) error {
+	res, err := s.DB.ExecContext(ctx, `DELETE FROM hosts WHERE id = ?`, id)
+	if err != nil {
+		return fmt.Errorf("delete host: %w", err)
+	}
+	n, _ := res.RowsAffected()
+	if n == 0 {
+		return ErrNotFound
+	}
+	return nil
+}
+
+func normalizeMAC(m string) string {
+	return strings.ToLower(strings.TrimSpace(m))
+}