fix: improve import, evidence indexing and material-scoped grading

Preserve document revisions and evidence, harden indexing and export behavior, add explicit material selection and direct-folder import, validate model JSON schemas with safe error messages, and retain student selection while loading scoring data.

backend/tests/test_batch_selection.py

@@ -0,0 +1,72 @@
+"""Explicit batch membership regressions, isolated from real grading and credentials."""
+import pytest
+from fastapi import HTTPException
+from pydantic import ValidationError
+from sqlalchemy import create_engine
+from sqlalchemy.orm import Session
+
+from wisegrade import api, services
+from wisegrade.db import Base
+from wisegrade.models import CourseVersion, Project, ScoringBatch, Student
+from wisegrade.seed import seed_initial
+
+
+@pytest.fixture
+def batch_db(environment):
+    engine = create_engine("sqlite://")
+    Base.metadata.create_all(engine)
+    with Session(engine, expire_on_commit=False) as db:
+        seed_initial(db)
+        students = [Student(student_no=f"900000000{i}", name=f"测试{i}") for i in (1, 2, 3)]
+        db.add_all(students)
+        db.flush()
+        other = CourseVersion(course_id=1, version=2, title="另一课程版本", published=True,
+                              objectives=[], indicators=[], directions=[], prompts={}, templates=[])
+        db.add(other)
+        db.flush()
+        db.add_all([Project(student_id=students[0].id, course_version_id=1, topic="项目甲", source_dir="a"),
+                    Project(student_id=students[1].id, course_version_id=1, topic="项目乙", source_dir="b"),
+                    Project(student_id=students[2].id, course_version_id=other.id, topic="其他版本", source_dir="c")])
+        db.commit()
+        yield db
+    engine.dispose()
+
+
+def test_select_one_project_and_preserve_batch_membership(batch_db):
+    data = api.BatchInput(course_version_id=1, rubric_version_id=1, project_ids=[2])
+    created = api.create_batch(data, batch_db)
+    batch = batch_db.get(ScoringBatch, created["id"])
+    assert batch.project_ids == [2]
+    # Importing another project later cannot change this batch's selected membership.
+    batch_db.add(Project(student_id=1, course_version_id=1, topic="后来导入", source_dir="later"))
+    batch_db.commit()
+    assert api.batch_progress(batch.id, batch_db)["project_ids"] == [2]
+
+
+def test_omitted_selection_preserves_existing_all_projects_api(batch_db):
+    created = api.create_batch(api.BatchInput(course_version_id=1, rubric_version_id=1), batch_db)
+    assert batch_db.get(ScoringBatch, created["id"]).project_ids == [1, 2]
+
+
+@pytest.mark.parametrize("ids", [[999], [3], [2, 2]])
+def test_reject_unknown_cross_version_and_duplicate_project_ids(batch_db, ids):
+    with pytest.raises(HTTPException) as exc:
+        api.create_batch(api.BatchInput(course_version_id=1, rubric_version_id=1, project_ids=ids), batch_db)
+    assert exc.value.status_code == 400
+    assert batch_db.query(ScoringBatch).count() == 0
+
+
+def test_empty_explicit_selection_cannot_silently_grade_everyone():
+    with pytest.raises(ValidationError):
+        api.BatchInput(course_version_id=1, rubric_version_id=1, project_ids=[])
+
+
+def test_batch_list_uses_saved_human_readable_version_metadata(batch_db):
+    created = api.create_batch(api.BatchInput(course_version_id=1, rubric_version_id=1, project_ids=[1]), batch_db)
+    batch = batch_db.get(ScoringBatch, created["id"])
+    batch.course_snapshot = {**batch.course_snapshot, "version": 7, "title": "创建时课程"}
+    batch.rubric_snapshot = {**batch.rubric_snapshot, "version": 9}
+    batch_db.commit()
+    listed = api.list_batches(batch_db)[0]
+    assert listed["course_version"] == 7 and listed["course_title"] == "创建时课程"
+    assert listed["rubric_version"] == 9 and listed["criterion_count"] == 22