diff --git a/internal/database/project_fact_version.go b/internal/database/project_fact_version.go
deleted file mode 100644
index cf49eecb..00000000
--- a/internal/database/project_fact_version.go
+++ /dev/null
@@ -1,144 +0,0 @@
-package database
-
-import (
-	"database/sql"
-	"fmt"
-	"strings"
-	"time"
-
-	"github.com/google/uuid"
-)
-
-// ProjectFactVersion 事实历史快照（同 fact_key 更新前归档）。
-type ProjectFactVersion struct {
-	ID                     string    `json:"id"`
-	FactID                 string    `json:"fact_id"`
-	ProjectID              string    `json:"project_id"`
-	FactKey                string    `json:"fact_key"`
-	Category               string    `json:"category"`
-	Summary                string    `json:"summary"`
-	Body                   string    `json:"body"`
-	Confidence             string    `json:"confidence"`
-	SourceConversationID   string    `json:"source_conversation_id,omitempty"`
-	SourceMessageID        string    `json:"source_message_id,omitempty"`
-	Pinned                 bool      `json:"pinned"`
-	RelatedVulnerabilityID string    `json:"related_vulnerability_id,omitempty"`
-	ArchivedAt             time.Time `json:"archived_at"`
-}
-
-// InsertProjectFactVersion 将当前事实行快照写入版本表。
-func (db *DB) InsertProjectFactVersion(f *ProjectFact) (string, error) {
-	if f == nil || f.ID == "" {
-		return "", fmt.Errorf("无效的事实记录")
-	}
-	id := uuid.New().String()
-	now := time.Now()
-	_, err := db.Exec(
-		`INSERT INTO project_fact_versions (
-			id, fact_id, project_id, fact_key, category, summary, body, confidence,
-			source_conversation_id, source_message_id, pinned, related_vulnerability_id, archived_at
-		) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
-		id, f.ID, f.ProjectID, f.FactKey, f.Category, f.Summary, f.Body, f.Confidence,
-		nullIfEmpty(f.SourceConversationID), nullIfEmpty(f.SourceMessageID), boolToInt(f.Pinned),
-		nullIfEmpty(f.RelatedVulnerabilityID), now,
-	)
-	if err != nil {
-		return "", fmt.Errorf("归档事实版本失败: %w", err)
-	}
-	return id, nil
-}
-
-// GetProjectFactVersion 按版本 ID 获取快照。
-func (db *DB) GetProjectFactVersion(versionID string) (*ProjectFactVersion, error) {
-	row := db.QueryRow(
-		`SELECT id, fact_id, project_id, fact_key, category, summary, COALESCE(body,''), confidence,
-			COALESCE(source_conversation_id,''), COALESCE(source_message_id,''), pinned,
-			COALESCE(related_vulnerability_id,''), archived_at
-		 FROM project_fact_versions WHERE id = ?`, versionID,
-	)
-	return scanProjectFactVersionRow(row)
-}
-
-// ListProjectFactVersions 列出某条事实的全部历史版本（新→旧）。
-func (db *DB) ListProjectFactVersions(factID string, limit int) ([]*ProjectFactVersion, error) {
-	if limit <= 0 {
-		limit = 20
-	}
-	rows, err := db.Query(
-		`SELECT id, fact_id, project_id, fact_key, category, summary, COALESCE(body,''), confidence,
-			COALESCE(source_conversation_id,''), COALESCE(source_message_id,''), pinned,
-			COALESCE(related_vulnerability_id,''), archived_at
-		 FROM project_fact_versions WHERE fact_id = ? ORDER BY archived_at DESC LIMIT ?`,
-		factID, limit,
-	)
-	if err != nil {
-		return nil, err
-	}
-	defer rows.Close()
-	var out []*ProjectFactVersion
-	for rows.Next() {
-		v, err := scanProjectFactVersionFromRows(rows)
-		if err != nil {
-			return nil, err
-		}
-		out = append(out, v)
-	}
-	return out, rows.Err()
-}
-
-func projectFactContentChanged(existing, incoming *ProjectFact) bool {
-	if existing == nil || incoming == nil {
-		return false
-	}
-	mergedBody := mergeFactBodyOnUpdate(incoming.Body, existing.Body)
-	inCat := stringsTrimDefault(incoming.Category, existing.Category)
-	inConf := stringsTrimDefault(incoming.Confidence, existing.Confidence)
-	return existing.Summary != incoming.Summary ||
-		existing.Body != mergedBody ||
-		existing.Category != inCat ||
-		existing.Confidence != inConf
-}
-
-func stringsTrimDefault(s, fallback string) string {
-	if strings.TrimSpace(s) == "" {
-		return fallback
-	}
-	return strings.TrimSpace(s)
-}
-
-func scanProjectFactVersionRow(row *sql.Row) (*ProjectFactVersion, error) {
-	var v ProjectFactVersion
-	var pinned int
-	var archivedAt string
-	err := row.Scan(
-		&v.ID, &v.FactID, &v.ProjectID, &v.FactKey, &v.Category, &v.Summary, &v.Body, &v.Confidence,
-		&v.SourceConversationID, &v.SourceMessageID, &pinned,
-		&v.RelatedVulnerabilityID, &archivedAt,
-	)
-	if err != nil {
-		if err == sql.ErrNoRows {
-			return nil, fmt.Errorf("事实版本不存在")
-		}
-		return nil, err
-	}
-	v.Pinned = pinned != 0
-	v.ArchivedAt = parseDBTime(archivedAt)
-	return &v, nil
-}
-
-func scanProjectFactVersionFromRows(rows *sql.Rows) (*ProjectFactVersion, error) {
-	var v ProjectFactVersion
-	var pinned int
-	var archivedAt string
-	err := rows.Scan(
-		&v.ID, &v.FactID, &v.ProjectID, &v.FactKey, &v.Category, &v.Summary, &v.Body, &v.Confidence,
-		&v.SourceConversationID, &v.SourceMessageID, &pinned,
-		&v.RelatedVulnerabilityID, &archivedAt,
-	)
-	if err != nil {
-		return nil, err
-	}
-	v.Pinned = pinned != 0
-	v.ArchivedAt = parseDBTime(archivedAt)
-	return &v, nil
-}