feat(protbot): add boost and gacha inspection scenarios

Adds non-destructive test scenarios for the #187 boost-time fix and
the #175 / gacha-logging changes so regressions in those paths can be
caught without a full game client.

- boost: queries GET_BOOST_TIME_LIMIT, GET_BOOST_RIGHT, and
  GET_KEEP_LOGIN_BOOST_STATUS, flagging a zero boost_limit and all-zero
  login boost entries as the expected DisableBoostTime/DisableLoginBoost
  state.
- gacha: snapshots GET_GACHA_POINT and RECEIVE_GACHA_ITEM (freeze=true,
  so temp storage is not cleared), with an opt-in --roll flag that
  exercises PLAY_NORMAL_GACHA end-to-end. Detects the post-#175
  single-byte validation-failure ACK.

cmd/protbot/scenario/boost.go

@@ -0,0 +1,113 @@
+package scenario
+
+import (
+	"fmt"
+	"time"
+
+	"erupe-ce/cmd/protbot/protocol"
+	"erupe-ce/common/byteframe"
+)
+
+// BoostTimeStatus holds the parsed response of MSG_MHF_GET_BOOST_TIME_LIMIT.
+// When boost time is disabled server-side, or has not been started yet,
+// BoostLimitUnix is 0. Prior to the #187 fix, unset boost_time columns
+// wrapped to a large uint32 the client interpreted as permanently active.
+type BoostTimeStatus struct {
+	BoostLimitUnix uint32
+}
+
+// BoostRight holds the parsed response of MSG_MHF_GET_BOOST_RIGHT.
+// 0 = disabled, 1 = active, 2 = available.
+type BoostRight struct {
+	State uint32
+}
+
+// LoginBoostEntry holds a single entry of the 5-entry MSG_MHF_GET_KEEP_LOGIN_BOOST_STATUS response.
+type LoginBoostEntry struct {
+	WeekReq    uint8
+	Active     bool
+	WeekCount  uint8
+	Expiration uint32
+}
+
+// LoginBoostStatus holds the full parsed keep login boost status response.
+type LoginBoostStatus struct {
+	Entries []LoginBoostEntry
+}
+
+// GetBoostTimeLimit sends MSG_MHF_GET_BOOST_TIME_LIMIT and parses the response.
+func GetBoostTimeLimit(ch *protocol.ChannelConn) (*BoostTimeStatus, error) {
+	ack := ch.NextAckHandle()
+	pkt := protocol.BuildGetBoostTimeLimitPacket(ack)
+	fmt.Printf("[boost] Sending GET_BOOST_TIME_LIMIT (ackHandle=%d)...\n", ack)
+	if err := ch.SendPacket(pkt); err != nil {
+		return nil, fmt.Errorf("get boost time limit send: %w", err)
+	}
+	resp, err := ch.WaitForAck(ack, 10*time.Second)
+	if err != nil {
+		return nil, fmt.Errorf("get boost time limit ack: %w", err)
+	}
+	if resp.ErrorCode != 0 {
+		return nil, fmt.Errorf("get boost time limit failed: error code %d", resp.ErrorCode)
+	}
+	if len(resp.Data) < 4 {
+		return nil, fmt.Errorf("get boost time limit response too short: %d bytes", len(resp.Data))
+	}
+	bf := byteframe.NewByteFrameFromBytes(resp.Data)
+	return &BoostTimeStatus{BoostLimitUnix: bf.ReadUint32()}, nil
+}
+
+// GetBoostRight sends MSG_MHF_GET_BOOST_RIGHT and parses the response.
+func GetBoostRight(ch *protocol.ChannelConn) (*BoostRight, error) {
+	ack := ch.NextAckHandle()
+	pkt := protocol.BuildGetBoostRightPacket(ack)
+	fmt.Printf("[boost] Sending GET_BOOST_RIGHT (ackHandle=%d)...\n", ack)
+	if err := ch.SendPacket(pkt); err != nil {
+		return nil, fmt.Errorf("get boost right send: %w", err)
+	}
+	resp, err := ch.WaitForAck(ack, 10*time.Second)
+	if err != nil {
+		return nil, fmt.Errorf("get boost right ack: %w", err)
+	}
+	if resp.ErrorCode != 0 {
+		return nil, fmt.Errorf("get boost right failed: error code %d", resp.ErrorCode)
+	}
+	if len(resp.Data) < 4 {
+		return nil, fmt.Errorf("get boost right response too short: %d bytes", len(resp.Data))
+	}
+	bf := byteframe.NewByteFrameFromBytes(resp.Data)
+	return &BoostRight{State: bf.ReadUint32()}, nil
+}
+
+// GetKeepLoginBoostStatus sends MSG_MHF_GET_KEEP_LOGIN_BOOST_STATUS and parses the response.
+// The server returns either 35 bytes (5 entries × 7 bytes) or 35 zero bytes
+// when DisableLoginBoost is set.
+func GetKeepLoginBoostStatus(ch *protocol.ChannelConn) (*LoginBoostStatus, error) {
+	ack := ch.NextAckHandle()
+	pkt := protocol.BuildGetKeepLoginBoostStatusPacket(ack)
+	fmt.Printf("[boost] Sending GET_KEEP_LOGIN_BOOST_STATUS (ackHandle=%d)...\n", ack)
+	if err := ch.SendPacket(pkt); err != nil {
+		return nil, fmt.Errorf("get login boost status send: %w", err)
+	}
+	resp, err := ch.WaitForAck(ack, 10*time.Second)
+	if err != nil {
+		return nil, fmt.Errorf("get login boost status ack: %w", err)
+	}
+	if resp.ErrorCode != 0 {
+		return nil, fmt.Errorf("get login boost status failed: error code %d", resp.ErrorCode)
+	}
+	if len(resp.Data) < 35 {
+		return nil, fmt.Errorf("login boost status response too short: %d bytes", len(resp.Data))
+	}
+	bf := byteframe.NewByteFrameFromBytes(resp.Data)
+	status := &LoginBoostStatus{}
+	for i := 0; i < 5; i++ {
+		status.Entries = append(status.Entries, LoginBoostEntry{
+			WeekReq:    bf.ReadUint8(),
+			Active:     bf.ReadBool(),
+			WeekCount:  bf.ReadUint8(),
+			Expiration: bf.ReadUint32(),
+		})
+	}
+	return status, nil
+}