feat(education): complete Flyway migration and atomic submit

docs/education/migration/issues/EDU-002-practice-regression-baseline.md

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+# EDU-002 — Restore the full Practice regression baseline
+
+- **Status:** completed as test-context repair; PostgreSQL persistence coverage moved to EDU-016
+- **Type:** test-enablement vertical slice
+- **Phase:** 0 / Phase 2 prerequisite
+- **Blockers:** EDU-001
+
+## Outcome
+
+The complete Practice test set starts reliably and distinguishes test-context failures from real behavior regressions across create, answer, restore, submit, report, wrong-question, and favorite flows.
+
+## Why this is next
+
+The direct EDU-001 tests pass, but broader Practice tests currently fail during Spring test-context creation because test configurations that import `PracticeSessionServiceImpl` do not consistently provide its current `ScoringService` dependency. Some tests also use name-based `@Resource` injection against Mapper proxies, producing type mismatches. Continuing core-loop work without this feedback loop would hide regressions.
+
+## Existing code and data
+
+- No legacy capability is being newly migrated.
+- No database object changes are required.
+- Existing Education test SQL and Mapper test infrastructure are reused.
+
+## Scope
+
+1. Inventory every test that imports, instantiates, or indirectly creates `PracticeSessionServiceImpl`.
+2. For each test context, choose one explicit dependency strategy:
+   - import the real `ScoringServiceImpl` when scoring behavior is under test; or
+   - provide `@MockitoBean ScoringService` when the test is outside the scoring seam.
+3. Replace ambiguous name-based Mapper injection only where it currently prevents the target tests from starting.
+4. Run the complete focused Practice regression set.
+5. Classify remaining failures as:
+   - test assembly defect;
+   - existing product defect;
+   - expected contract change from EDU-001;
+   - unrelated dirty-worktree issue.
+6. Fix only test-assembly defects in this ticket. Create separate tickets for product defects.
+
+## Reuse boundaries
+
+- Reuse `BaseDbUnitTest`, existing Education test SQL, Spring `@Import`, and `@MockitoBean`.
+- Do not create a parallel test framework.
+- Do not modify System, Member, database schema, or production state machines.
+- Do not weaken assertions merely to make tests green.
+
+## Target test set
+
+```text
+PracticeSessionServiceImplTest
+PracticeAnswerServiceImplTest
+PracticeSubmitServiceImplTest
+PracticeSubmitProjectionIntegrationTest
+PracticeSessionControllerHttpTest
+PracticeAnswerControllerHttpTest
+PracticeSessionControllerSubmitHttpTest
+WrongQuestionServiceImplTest
+FavoriteServiceImplTest
+```
+
+## Acceptance criteria
+
+- [ ] Every target class starts its Spring/JUnit context.
+- [ ] No target class fails because `ScoringService` is missing.
+- [ ] No target class fails from avoidable Mapper bean-name/type injection ambiguity.
+- [ ] EDU-001 safe-content assertions remain green.
+- [ ] Any actual behavior failure is documented with reproducible command and assigned a separate ticket.
+- [ ] No production behavior or database schema is changed unless a failing regression proves it is necessary and the ticket is explicitly amended.
+
+## Test command
+
+```bash
+mvn -pl yudao-module-education \
+  -Dtest='PracticeSessionServiceImplTest,PracticeAnswerServiceImplTest,PracticeSubmitServiceImplTest,PracticeSubmitProjectionIntegrationTest,PracticeSessionControllerHttpTest,PracticeAnswerControllerHttpTest,PracticeSessionControllerSubmitHttpTest,WrongQuestionServiceImplTest,FavoriteServiceImplTest' \
+  -Dsurefire.failIfNoSpecifiedTests=false \
+  test
+```
+
+Then:
+
+```bash
+git diff --check
+mvn -pl yudao-server -am -DskipTests clean compile
+```
+
+## Risk and rollback
+
+- **Risk:** Low production risk; medium risk of exposing pre-existing behavior defects.
+- **Rollback:** Revert only this ticket's test assembly changes. There is no database rollback.
+
+## Completion result
+
+Test-context assembly was repaired:
+
+- `ScoringService` is now explicitly mocked in Practice contexts that are not testing scoring itself.
+- `PracticeQuestionMapper` fields use type-based injection where name-based `@Resource` resolved the wrong MyBatis proxy.
+- Controller tests and `PracticeSessionServiceImplTest` start and pass.
+
+The expanded regression run then exposed a separate infrastructure limitation rather than a remaining Spring context defect: H2 cannot execute the production PostgreSQL `ON CONFLICT` statements, and the unified `education_idempotency` test table was missing. A temporary H2 table definition was added so table absence no longer masks the dialect issue, but PostgreSQL conflict semantics cannot be made truthful on H2. The required follow-up is [`EDU-016`](EDU-016-postgresql-persistence-tests.md).
+
+## Verification result
+
+- Controller Practice tests: 39 passed.
+- `PracticeSessionServiceImplTest`: 24 passed before PostgreSQL-dialect persistence paths were included.
+- Full targeted suite starts after dependency/injection repair, then fails on confirmed H2/PostgreSQL dialect mismatch and downstream assertions.
+- No production behavior was changed by EDU-002.
+