feat: complete SyncServer implementation

Full-stack Go monolith with embedded React frontend for orchestrating
rsync-over-SSH file synchronization with Wake-on-LAN support.

Features:
- JWT auth (HS256) with bcrypt password hashing
- CRUD for machines (with WoL config) and sync_pairs
- Ed25519 SSH key generation and known_hosts management
- WoL magic packet sender + TCP-connect waiter with backoff
- Sync engine: rsync subprocess, per-pair job queue, progress parsing
- Homebrew cron parser for scheduled syncs
- SSE stream for live job status (queued/waking_up/running/success/failed)
- React+TS+Vite+Tailwind SPA embedded via embed.FS
- Debian packaging with systemd unit, postinst/prerm/postrm

Tech stack:
- Go 1.22+ (CGO_ENABLED=0, pure SQLite via modernc.org/sqlite)
- chi router for HTTP API
- TypeScript + React 18 + Tailwind CSS frontend
- Cross-compiled to Linux amd64 for Proxmox LXC deployment

Tests: wol (MAC parsing, magic packet), syncengine/queue, scheduler/cron

internal/models/machine.go

@@ -0,0 +1,161 @@
+package models
+
+import (
+	"database/sql"
+	"time"
+)
+
+type Machine struct {
+	ID                          int64      `db:"id" json:"id"`
+	Name                        string     `db:"name" json:"name"`
+	Host                        string     `db:"host" json:"host"`
+	Port                        int        `db:"port" json:"port"`
+	SSHUser                     string     `db:"ssh_user" json:"ssh_user"`
+	SSHKeyID                    *int64     `db:"ssh_key_id" json:"ssh_key_id"`
+	MACAddress                  *string    `db:"mac_address" json:"mac_address"`
+	WoLEnabled                  bool       `db:"wol_enabled" json:"wol_enabled"`
+	BroadcastAddr               *string    `db:"broadcast_addr" json:"broadcast_addr"`
+	WakeTimeoutSeconds          int        `db:"wake_timeout_seconds" json:"wake_timeout_seconds"`
+	WakeCheckIntervalSeconds    int        `db:"wake_check_interval_seconds" json:"wake_check_interval_seconds"`
+	FingerprintConfirmed        bool       `db:"fingerprint_confirmed" json:"fingerprint_confirmed"`
+	Status                      string     `db:"status" json:"status"`
+	LastSeenAt                  *time.Time `db:"last_seen_at" json:"last_seen_at"`
+	CreatedAt                   time.Time  `db:"created_at" json:"created_at"`
+}
+
+type MachineRepository struct {
+	db *sql.DB
+}
+
+func NewMachineRepository(db *sql.DB) *MachineRepository {
+	return &MachineRepository{db: db}
+}
+
+func (r *MachineRepository) Create(m *Machine) (int64, error) {
+	res, err := r.db.Exec(`
+		INSERT INTO machines (name, host, port, ssh_user, ssh_key_id, mac_address,
+			wol_enabled, broadcast_addr, wake_timeout_seconds, wake_check_interval_seconds,
+			fingerprint_confirmed, status)
+		VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
+		m.Name, m.Host, m.Port, m.SSHUser, m.SSHKeyID, m.MACAddress,
+		boolToInt(m.WoLEnabled), m.BroadcastAddr, m.WakeTimeoutSeconds,
+		m.WakeCheckIntervalSeconds, boolToInt(m.FingerprintConfirmed), m.Status,
+	)
+	if err != nil {
+		return 0, err
+	}
+	return res.LastInsertId()
+}
+
+func (r *MachineRepository) GetAll() ([]Machine, error) {
+	rows, err := r.db.Query(`
+		SELECT id, name, host, port, ssh_user, ssh_key_id, mac_address,
+			wol_enabled, broadcast_addr, wake_timeout_seconds, wake_check_interval_seconds,
+			fingerprint_confirmed, status, last_seen_at, created_at
+		FROM machines ORDER BY name`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var ms []Machine
+	for rows.Next() {
+		var m Machine
+		var mac, bcast sql.NullString
+		var keyID sql.NullInt64
+		var lastSeen sql.NullTime
+		err := rows.Scan(&m.ID, &m.Name, &m.Host, &m.Port, &m.SSHUser, &keyID,
+			&mac, &m.WoLEnabled, &bcast, &m.WakeTimeoutSeconds,
+			&m.WakeCheckIntervalSeconds, &m.FingerprintConfirmed,
+			&m.Status, &lastSeen, &m.CreatedAt)
+		if err != nil {
+			return nil, err
+		}
+		if keyID.Valid {
+			v := keyID.Int64
+			m.SSHKeyID = &v
+		}
+		if mac.Valid {
+			m.MACAddress = &mac.String
+		}
+		if bcast.Valid {
+			m.BroadcastAddr = &bcast.String
+		}
+		if lastSeen.Valid {
+			m.LastSeenAt = &lastSeen.Time
+		}
+		ms = append(ms, m)
+	}
+	return ms, rows.Err()
+}
+
+func (r *MachineRepository) GetByID(id int64) (*Machine, error) {
+	var m Machine
+	var mac, bcast sql.NullString
+	var keyID sql.NullInt64
+	var lastSeen sql.NullTime
+	err := r.db.QueryRow(`
+		SELECT id, name, host, port, ssh_user, ssh_key_id, mac_address,
+			wol_enabled, broadcast_addr, wake_timeout_seconds, wake_check_interval_seconds,
+			fingerprint_confirmed, status, last_seen_at, created_at
+		FROM machines WHERE id = ?`, id).Scan(
+		&m.ID, &m.Name, &m.Host, &m.Port, &m.SSHUser, &keyID,
+		&mac, &m.WoLEnabled, &bcast, &m.WakeTimeoutSeconds,
+		&m.WakeCheckIntervalSeconds, &m.FingerprintConfirmed,
+		&m.Status, &lastSeen, &m.CreatedAt)
+	if err != nil {
+		return nil, err
+	}
+	if keyID.Valid {
+		v := keyID.Int64
+		m.SSHKeyID = &v
+	}
+	if mac.Valid {
+		m.MACAddress = &mac.String
+	}
+	if bcast.Valid {
+		m.BroadcastAddr = &bcast.String
+	}
+	if lastSeen.Valid {
+		m.LastSeenAt = &lastSeen.Time
+	}
+	return &m, nil
+}
+
+func (r *MachineRepository) Update(m *Machine) error {
+	_, err := r.db.Exec(`
+		UPDATE machines SET name=?, host=?, port=?, ssh_user=?, ssh_key_id=?,
+			mac_address=?, wol_enabled=?, broadcast_addr=?, wake_timeout_seconds=?,
+			wake_check_interval_seconds=?, fingerprint_confirmed=?, status=?, last_seen_at=?
+		WHERE id=?`,
+		m.Name, m.Host, m.Port, m.SSHUser, m.SSHKeyID, m.MACAddress,
+		boolToInt(m.WoLEnabled), m.BroadcastAddr, m.WakeTimeoutSeconds,
+		m.WakeCheckIntervalSeconds, boolToInt(m.FingerprintConfirmed),
+		m.Status, m.LastSeenAt, m.ID,
+	)
+	return err
+}
+
+func (r *MachineRepository) Delete(id int64) error {
+	_, err := r.db.Exec("DELETE FROM machines WHERE id = ?", id)
+	return err
+}
+
+func (r *MachineRepository) UpdateStatus(id int64, status string) error {
+	_, err := r.db.Exec(
+		"UPDATE machines SET status = ?, last_seen_at = CURRENT_TIMESTAMP WHERE id = ?",
+		status, id,
+	)
+	return err
+}
+
+func boolToInt(b bool) int {
+	if b {
+		return 1
+	}
+	return 0
+}
+
+func intToBool(i int) bool {
+	return i != 0
+}