Persist candidate scope scrub state across restarts

Why: A crash after dropping candidate raw prompt columns but before SQLite compaction left physical prompt bytes without a visible reason to retry, and storage backup could accept that file.

Evidence: RED post-commit interruption and pending-backup tests; full Go suite, targeted race, isolated PostgreSQL package tests, vet, and build passed locally before commit.

Impact: Commit a durable pending marker with v35, retry compaction and WAL truncation until completion, conservatively re-scrub earlier v35 candidates, and reject backup or migration while cleanup is pending or unverified.

Refs: Approved RDM stage6 W6 source-recheck design adjustment r1; W6 independent review crash-window finding.

cmd/storage-migrate/main.go

@@ -430,6 +430,21 @@ func refuseCandidateRawContextScope(db *sql.DB) error {
 	if columns > 0 {
 		return fmt.Errorf("candidate context scope text columns remain; isolate and scrub source before backup or migration")
 	}
+	var version int
+	if sqliteHasTable(db, "schema_migrations") {
+		if err := db.QueryRow(`SELECT COALESCE(MAX(version),0) FROM schema_migrations`).Scan(&version); err != nil {
+			return err
+		}
+	}
+	if version >= 34 {
+		if !sqliteHasTable(db, "context_scope_scrub_state") {
+			return fmt.Errorf("candidate context physical scrub marker missing; isolate and scrub source before backup or migration")
+		}
+		var pending int
+		if err := db.QueryRow(`SELECT pending FROM context_scope_scrub_state WHERE id=1`).Scan(&pending); err != nil || pending != 0 {
+			return fmt.Errorf("candidate context physical scrub pending or unverified; isolate and scrub source before backup or migration")
+		}
+	}
 	return nil
 }
 

cmd/storage-migrate/main_test.go

@@ -173,7 +173,8 @@ func TestCopyOrderCoversAllFixtureTables(t *testing.T) {
 	for _, t := range copyOrder {
 		known[t] = true
 	}
-	known["schema_migrations"] = true // 迁移器管理，不随迁
+	known["schema_migrations"] = true         // 迁移器管理，不随迁
+	known["context_scope_scrub_state"] = true // SQLite 候选原文物理清理状态，不随迁
 	// 运行态表不随迁：执行许可是进程瞬态；执行租约与跨实例命令属当前
 	// 实例的调度现场（接管语义在 U5 内由 lease/fencing 处理，不复制历史）。
 	for _, rt := range []string{"admission_leases", "conversation_executions", "run_commands"} {
@@ -248,3 +249,58 @@ func TestBackupAndMigrateRejectCandidateRawContextScope(t *testing.T) {
 		t.Fatal("backup retained candidate raw scope body")
 	}
 }
+
+func TestBackupAndMigrateRejectPendingOrMissingContextScrubMarker(t *testing.T) {
+	path := buildFixture(t)
+	db, err := sql.Open("sqlite", path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, query := range []string{
+		`CREATE TABLE IF NOT EXISTS context_scope_scrub_state(id INTEGER PRIMARY KEY,pending INTEGER NOT NULL)`,
+		`INSERT OR REPLACE INTO context_scope_scrub_state(id,pending) VALUES(1,1)`,
+	} {
+		if _, err := db.Exec(query); err != nil {
+			t.Fatal(err)
+		}
+	}
+	if err := db.Close(); err != nil {
+		t.Fatal(err)
+	}
+	assertRejected := func(name string) {
+		t.Helper()
+		out := filepath.Join(t.TempDir(), name+".db")
+		if err := cmdBackup([]string{"--source", path, "--out", out}); err == nil {
+			t.Fatalf("backup accepted %s context scrub state", name)
+		}
+		if _, err := os.Stat(out); !os.IsNotExist(err) {
+			t.Fatalf("rejected %s backup created output: %v", name, err)
+		}
+		if err := cmdMigrate([]string{"--source", path, "--target", "postgres://invalid", "--migration-id", name}); err == nil {
+			t.Fatalf("migration accepted %s context scrub state", name)
+		}
+	}
+	assertRejected("pending")
+	db, err = sql.Open("sqlite", path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := db.Exec(`DROP TABLE context_scope_scrub_state`); err != nil {
+		t.Fatal(err)
+	}
+	if err := db.Close(); err != nil {
+		t.Fatal(err)
+	}
+	assertRejected("missing")
+	db, err = sql.Open("sqlite", path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := db.Exec(`DELETE FROM schema_migrations WHERE version=35`); err != nil {
+		t.Fatal(err)
+	}
+	if err := db.Close(); err != nil {
+		t.Fatal(err)
+	}
+	assertRejected("v34-missing")
+}