solution-erp/.claude/skills/ef-core-migration/SKILL.md

name, description, when-to-use

name	description	when-to-use
ef-core-migration	Tạo/sửa/revert EF Core 10 migration cho SOLUTION_ERP. Dùng khi thêm entity mới, thay đổi schema, rollback migration, debug DesignTimeDbContextFactory fail. Đã có 43 migration sẵn (Init → FilterHolidayUniqueIndexByIsDeleted Mig 43, S45). Snapshot + Designer + Migration 3-file rule bắt buộc commit đủ.	thêm migration EF Core migration dotnet ef migrations add revert migration schema DB update DbContext change snapshot lỗi DesignTimeDbContextFactory

EF Core Migration — SOLUTION_ERP

Context: .NET 10 + EF Core 10 + SQL Server. DbContext: ApplicationDbContext ở Infrastructure/Persistence/. Startup: SolutionErp.Api.

Migration history (43 migration hiện có)

#	Name	Tables added / changed
1	Init	7 Identity tables (AspNetUsers/Roles/UserRoles/...)
2	AddMasterData	Suppliers, Projects, Departments
3	AddPermissions	MenuItems, Permissions
4	AddForms	ContractTemplates, ContractClauses
5	AddContractsWorkflow	Contracts, ContractApprovals, ContractComments, ContractAttachments, ContractCodeSequences
6	AddNotifications	Notifications
7	AddWorkflowTypeAssignments	WorkflowTypeAssignments (legacy admin override)
8	AddVersionedWorkflows	WorkflowDefinitions, WorkflowSteps, WorkflowStepApprovers + Contracts.WorkflowDefinitionId FK
9	AddContractDetailsAndChangelog	7 per-type Details (ThauPhu/GiaoKhoan/NhaCungCap/DichVu/MuaBan/NguyenTacNcc/NguyenTacDv) + ContractChangelogs
10	AddMasterCatalogs	UnitsOfMeasure, MaterialItems, ServiceItems, WorkItems
11	AddRoleShortNameAndUserDepartment	+Role.ShortName + User.DepartmentId/Position (cột thêm, không bảng mới)
12	AddPurchaseEvaluations	10 bảng module Duyệt NCC: PurchaseEvaluations + Suppliers + Details + Quotes + Approvals + Changelogs + Attachments + WorkflowDefinitions/Steps/StepApprovers
13	AddPurchaseEvaluationCodeSequences	1 bảng PurchaseEvaluationCodeSequences (Prefix PK, LastSeq) — atomic sequence cho MaPhieu format PE/{YYYY}/{A|B}/{Seq:D3}
14	AddBudgets	4 bảng module Ngân sách: Budgets + BudgetDetails + BudgetApprovals + BudgetChangelogs. + nullable FK index Contracts.BudgetId & PurchaseEvaluations.BudgetId
15	AddPurchaseEvaluationDepartmentOpinions	1 bảng PurchaseEvaluationDepartmentOpinions (UNIQUE PEId+Kind, max 1 row mỗi PeDepartmentKind per phiếu — Phê duyệt/Ccm/MuaHang/SmPm)
16	AddTwoStageDeptApprovalAndSmartReject	3 bảng Contract/PurchaseEvaluation/Budget DepartmentApprovals (UNIQUE TargetId+Phase+Dept+Stage cho 2-stage NV.Review → TPB.Confirm per phòng × phase) + 4 ALTER (Users.CanBypassReview bit cho NV bypass + 3 RejectedFromPhase int cho smart reject jump-back). Phase 9 — đóng bug "NV duyệt được hết phase" anh Kiệt (FDC) báo. Logic 2-stage trong PurchaseEvaluationWorkflowService chỉ áp PE; HĐ + Budget defer.
17	AddManualBudgetFieldsToPeAndContract	4 ALTER (PE + HĐ × BudgetManualName nvarchar(200) + BudgetManualAmount decimal(18,2)) — manual budget fallback khi user không link Budget entity approved. KHÔNG XOR với BudgetId, cả 2 cùng null OK. Carry-forward pe.BudgetManualName/Amount → contract ở CreateContractFromEvaluation. Phase 9 — Session 11 (2026-05-07).
18	AddPeWorkflowInnerStepsAndPositionLevel	N-stage workflow PE — 1 CREATE TABLE PurchaseEvaluationWorkflowStepInnerSteps (Order, DepartmentId, PositionLevel, Name, SlaDays, IsRequired) + 2 ALTER (Users.PositionLevel int? 1=NV/2=PP/3=TP + PEDeptApproval.InnerStepId Guid?) + 3 IX + FK Cascade Step / Restrict Dept+InnerStep. Phase 9+ — Session 12 (2026-05-07).
19	AlterPeDeptApprovalsUniqueFilteredForInnerSteps	Filtered unique split: drop UNIQUE cũ Mig 16 → 2 filtered: legacy WHERE InnerStepId IS NULL (Stage Review/Confirm) + N-stage WHERE InnerStepId IS NOT NULL (per inner step). Tránh conflict 2 inner step cùng dept Stage=Confirm. Session 12.
20	AddContractWorkflowInnerStepsAndAlterDeptApprovalUnique	N-stage workflow Contract mirror PE Mig 18+19 — GỘP 1 migration: CREATE TABLE WorkflowStepInnerSteps + ALTER ContractDeptApproval.InnerStepId + DropIndex old + Recreate filtered legacy/N-stage + 3 IX + FK. Session 13 (2026-05-07).
21	RefactorWorkflowToFlatModel	🎯 DRASTIC REFACTOR (Session 16, 2026-05-08): bỏ phase enum legacy, dùng ChoDuyet=10 đơn nhất + currentStepIndex tracking. Workflow flat (Phòng × Cấp + Approvers). 4 ALTER (PE/Contract +CurrentWorkflowStepIndex/RejectedAtStepIndex) + 2 ALTER (WorkflowStep +DepartmentId/PositionLevel PE+Contract) + DROP TABLE × 2 (PE+Contract WorkflowStepInnerSteps Mig 18+20) + DROP COLUMN InnerStepId × 2 + DROP filtered indexes Mig 19/20 + RESTORE simple unique non-filtered × 2.
22	AddApprovalWorkflowsV2	🎯 V2 schema mới (Session 17, 2026-05-08) — riêng cho UAT trước khi drop legacy V1. 3 entity ApprovalWorkflow + Step + Level + enum ApplicableType (DuyetNcc=1 / DuyetNccPhuongAn=2 / Contract=3). 3 CREATE TABLE + UNIQUE (Code, Version) + FK Cascade Step→Workflow + Level→Step + FK Restrict Department + ApproverUserId. Cấu trúc: Quy trình > Bước (Phòng) > Cấp (1 NV cụ thể qua ApproverUserId, OR-of-N rows cùng Order = same Cấp). DbInitializer +menu V2 + leaf AwV2_DuyetNcc/DuyetNccPhuongAn.
23	AddApprovalWorkflowIdToPurchaseEvaluation	Pin V2 vào PE — PE.ApprovalWorkflowId Guid? + EF FK Restrict. Workspace Select bắt buộc workflow lúc create + Validate ApplicableType match PE.Type. Session 17.
24	AddCurrentApprovalLevelOrderToPe	Service V2 wire — PE.CurrentApprovalLevelOrder int? track Cấp đang chờ trong Step hiện tại khi pin ApprovalWorkflowId. Null khi V1 legacy hoặc terminal. Service ApproveV2Async group Levels by Order = Cấp (OR-of-N), match actor.Id ∈ ApproverUserId, advance levelOrder++ trong Step → idx++ + reset levelOrder=1 → DaDuyet. Synthetic Policy ForV2Schema() cho FE nextPhases. Session 17.
25	AddIsUserSelectableToApprovalWorkflows	ALTER ApprovalWorkflows +IsUserSelectable bit NOT NULL DEFAULT 0 — admin pin/unpin workflow cho user pick lúc create phiếu (multi-select, độc lập IsActive — multiple version cùng selectable). Backfill WHERE IsActive=1 SET 1 giữ behavior cũ (active workflows vẫn pickable). Designer +badge "Cho user chọn" + button Ghim/Bỏ ghim + mutation toggle. Workspace dropdown filter isUserSelectable=true only. API PATCH /api/approval-workflows-v2/{id}/user-selectable admin-only. Session 18 (2026-05-08).
26	AddPeLevelOpinionsForV2	🎯 Section 5 dynamic theo Workflow V2 (Session 19, 2026-05-09) — bảng mới PurchaseEvaluationLevelOpinions UNIQUE composite (PEId, ApprovalWorkflowLevelId), FK Cascade Pe + Restrict Level. Comment nvarchar(2000) + SignedAt + SignedByUserId + SignedByFullName denorm. Service ApproveV2Async UPSERT auto khi NV duyệt (Q1=1B sync gắn với Duyệt, KHÔNG endpoint CRUD rời). Match level theo ApproverUserId; Admin override fallback first level (FE banner "Admin duyệt thay" khi SignedByUserId !== ApproverUserId). Comment empty → "(duyệt — không ý kiến)" placeholder Q4 bonus. Phiếu V1 legacy fallback Mig 15 4 box readOnly. Mig 15 deprecated cho V2 phiếu (drop sau UAT confirm Mig 27+).
27	AddVisibilityAndDisplayLabelToMenuItems	2 ALTER MenuItems (+IsVisible bit=1 +DisplayLabel nvarchar(200)?) — admin ẩn/hiện + đổi tên menu eOffice (fe-user). Không bảng mới. Session 20.
28	AddAdvancedOptionsToApprovalWorkflows	ALTER ApprovalWorkflows — advanced options (skip/optional level config). Session 22.
29	RefactorAdvancedOptionsToPerLevelAndDrafterUser	Refactor advanced options → per-ApprovalWorkflowLevel + DrafterUser scope. Session 22.
30	AddAllowApproverEditBudgetToLevels	ALTER ApprovalWorkflowLevels +AllowApproverEditBudget bit. Session 22.
31	RefactorSkipToFinalToApproverLevel	Per-Approver-slot skip-to-final (Level → Approver slot swap). Session 23.
32	AddApprovalWorkflowToContract	🎯 Contract V2 wire (Plan B S29) — 2 ALTER Contracts (+ApprovalWorkflowId Guid? +CurrentApprovalLevelOrder int?) cookie-cutter mirror PE Mig 23+24. Không bảng mới.
33	AddContractLevelOpinions	1 bảng ContractLevelOpinions (UNIQUE composite ContractId+LevelId, FK Cascade Contract + Restrict Level) — mirror PE Mig 26. Session 29.
34	AddEmployeeProfiles	HRM core — EmployeeProfiles + N satellite tables cùng parent (Pattern 12-ter). Session 34.
35	AddHrmConfigs	HRM config catalogs (LeaveTypes / Holidays UNIQUE composite / declarative KIND_CONFIG). Session 35.
36	AddMeetingRooms	Office — MeetingRooms + booking. Session 36-37.
37	ExtendApplicableTypeForWorkflowApps	Enum extend ApplicableType (+Proposal +WorkflowApps values). Không bảng mới. Session 37-38.
38	AddProposals	Module Đề xuất (Proposal) — tables + workflow V2 mirror PE/Contract. Session 37.
39	AddWorkflowApps	Workflow Apps skeleton — Leave/OT/Travel/Vehicle/Ticket request tables (Phase 10 Plan G-O4/O5). Session 38.
40	AddAttendances	Chấm công (Attendance) tables + Dashboard NS skeleton. Session 38.
41	WireWorkflowAppsApprovalV2	🎯 Phase 11 P11-A (S42) — +4 {Leave,Ot,Travel,Vehicle}LevelOpinions (UNIQUE composite + Cascade/Restrict) + WorkflowAppCodeSequences (atomic MaDonTu) + 4 ALTER RejectedFromStatus + enum TravelRequest=9.
42	AddLeaveBalances	🎯 Phase 11 P11-B (S43) — 1 bảng LeaveBalances (User×LeaveType×Year + Entitled/Used/Adjustment, UNIQUE composite + FK LeaveTypes Restrict). Trừ phép tự động khi đơn nghỉ duyệt cuối.
43	FilterHolidayUniqueIndexByIsDeleted	🎯 S45 — DropIndex + CreateIndex IX_Holidays_Year_Date UNIQUE filtered WHERE [IsDeleted]=0 (was unfiltered). Fix reachable 500 khi recreate ngày lễ trên slot soft-deleted. Không bảng mới (table vẫn 91). gotcha #57 — soft-delete UNIQUE phải filter.

Total: 91 bảng dbo + __EFMigrationsHistory (last Mig 43 FilterHolidayUniqueIndexByIsDeleted, index-only). Xem docs/database/schema-diagram.md migration table + §11-15 module ERD (§16+ Mig 27-42 chi tiết pending).

N-stage workflow pattern (Mig 18-20 — Session 12-13)

Architecture decision đáng ghi cho session sau:

Pattern: Mỗi WorkflowStep cha (= 1 phase) cấu hình động chuỗi InnerSteps con theo Department × PositionLevel với Order sequential. Approver cần khớp DeptId + PositionLevel + Order tiếp theo chưa duyệt. CanBypassReview cho user level cao hơn skip cấp dưới cùng dept.

Per-module migration (PE first, mirror sang Contract sau):

• PE: 2 migration tách (Mig 18 schema + Mig 19 alter index) — vì index issue phát hiện sau khi schema đã commit
• Contract: 1 migration GỘP (Mig 20) — gộp CREATE TABLE + ALTER + DropIndex + Recreate filtered. Cleaner cho mirror.

Filtered unique trick: legacy 2-stage rows (Mig 16, Stage=Review/Confirm) + N-stage rows (per InnerStep) cùng table *DepartmentApprovals → cần unique split:

• UX_*_Phase_Dept_Stage WHERE InnerStepId IS NULL (legacy, prevent duplicate Review/Confirm cùng phase × dept)
• UX_*_Phase_InnerStep WHERE InnerStepId IS NOT NULL (N-stage, prevent duplicate per inner step)

Backward compat 100%: workflow no InnerSteps configured → service fallback legacy 2-stage logic Mig 16. Data legacy InnerStepId=null vẫn enforce unique cũ qua filtered index.

Budget defer: Budget chưa có versioned WorkflowDefinition entity (hardcoded BudgetPolicy.Default). Để mirror N-stage Budget cần migration AddBudgetVersionedWorkflow trước (4 bảng + ALTER Budget.WorkflowDefinitionId?). Defer cho user quyết riêng.

Phase 7 pending:

• AddPePaymentTermFields — tách PurchaseEvaluations.PaymentTerms JSON thành 6 column riêng (Session 11+++++ đã thay UI Workspace <Textarea> JSON → <Select> 8 preset, BE schema vẫn nvarchar(max). Migration tách field defer cho khi BE cần aggregate/filter từng terms riêng)
• AddPeDepartmentOpinions — thêm 4 field Ý kiến phòng ban (Phê duyệt/CCM/MuaHàng/SM-PM) vào header hoặc table riêng (đã làm Mig 15 — bảng riêng UNIQUE PEId+Kind)

Phase 8 pending (Budget refinement):

• AddBudgetCodeSequences — atomic sequence khi format MaNganSach chốt (mirror Contract/PE pattern, hiện Random.Shared)
• AddBudgetVersionedWorkflow — nếu Solutions cần admin config UI (3 bảng BudgetWorkflowDefinitions/Steps/StepApprovers + Budgets.WorkflowDefinitionId?)

Phase 8 update (2026-04-29 Session 5):

• Migration 15 AddPurchaseEvaluationDepartmentOpinions — 1 bảng riêng (UNIQUE PEId+Kind), max 4 row mỗi phiếu cho 4 phòng ban (Phê duyệt/Ccm/MuaHang/SmPm). UPDATE in-place khi user đổi ý, audit qua Changelog.
• Tests: tests/SolutionErp.Domain.Tests/ (58 test policy state machine) + tests/SolutionErp.Infrastructure.Tests/ (96 test = codegen + 2-stage/N-stage + AuthorizePolicy + V2 actor scope + WorkflowApps ApproveV2 + LeaveBalance/guard). Total 154 test pass (current S43; S22-S25 baseline was 111). S22-S23 +20 cumulative regression: ReturnMode + DraftGuard + Reflection AuthorizePolicy + V2 actor scope reject + per-NV lookup discrimination (Plan N+O). Mig 21 drop 19 legacy (PE 2-stage S9 + PE N-stage S12 + Contract N-stage S13 + PE Reject S14) — flat workflow stabilized post-S22 V2 ground truth.
• CI optimize 3 fix (29/04):
  • Manual checkout bypass github.com (gotcha #39) — fix TCP timeout 21s
  • Path filter docs-only skip (gotcha #41) — commit MD-only KHÔNG trigger CI
  • npm junction cache (gotcha #40) — rolled back, debug session sau
• Migration verify pattern thêm: chạy dotnet test SolutionErp.slnx local trước mỗi migration commit để chống regression policy/codegen.

Phase 7 update (2026-04-28):

• Migration 14 AddBudgets — 4 bảng (Budgets/Details/Approvals/Changelogs) + 2 cột BudgetId? thêm vào Contracts & PurchaseEvaluations. Workflow hardcoded BudgetPolicy.Default (chưa versioned).
• 14 demo user thật @solutions.com.vn qua SeedDemoUsersAsync reconcile (PRO 5 + CCM 7 + ISO 1 + CEO 1).

Phase 6 update (2026-04-24):

• Enum PurchaseEvaluationAttachmentPurpose.ComparisonTable = 4 mới (file bảng so sánh tổng). Int column, không cần migration.
• BackfillUserEmailDomainAsync trong DbInitializer — rename in-place 4 field Email/NormalizedEmail/UserName/NormalizedUserName. Idempotent.

Commands (chạy từ root repo)

Thêm migration mới

# Sau khi chỉnh Domain entity + EF config + DbContext DbSet
dotnet ef migrations add <MigrationName> `
  --project src/Backend/SolutionErp.Infrastructure `
  --startup-project src/Backend/SolutionErp.Api `
  --output-dir Persistence/Migrations

Naming convention: PascalCase, verb prefix:

• Add<Thing> — thêm entity / bảng
• Update<Thing> — thay đổi schema
• Remove<Thing> — xóa column / table
• Rename<Thing> — đổi tên

Apply migration to DB

# Dev: LocalDB SolutionErp_Dev
dotnet ef database update `
  --project src/Backend/SolutionErp.Infrastructure `
  --startup-project src/Backend/SolutionErp.Api

# Hoặc đơn giản: chạy API → DbInitializer tự Migrate
dotnet run --project src/Backend/SolutionErp.Api

Revert 1 migration (rollback)

# Rollback về migration trước đó (ví dụ về sau AddWorkflowTypeAssignments)
dotnet ef database update AddWorkflowTypeAssignments `
  --project src/Backend/SolutionErp.Infrastructure `
  --startup-project src/Backend/SolutionErp.Api

# Xóa file migration (3 file, xem dưới)
dotnet ef migrations remove `
  --project src/Backend/SolutionErp.Infrastructure `
  --startup-project src/Backend/SolutionErp.Api

Gen SQL script (review trước khi apply prod)

# Script từ 1 migration → latest
dotnet ef migrations script AddWorkflowTypeAssignments `
  --project src/Backend/SolutionErp.Infrastructure `
  --startup-project src/Backend/SolutionErp.Api `
  --output tmp/migration-7-to-8.sql

# Idempotent (check if exists trước mỗi operation)
dotnet ef migrations script --idempotent `
  --project src/Backend/SolutionErp.Infrastructure `
  --startup-project src/Backend/SolutionErp.Api

3-file rule (BẮT BUỘC commit đủ)

Mỗi migrations add sinh 3 file — phải commit đủ:

src/Backend/SolutionErp.Infrastructure/Persistence/Migrations/
├── {Timestamp}_{Name}.cs              ← migration logic (Up/Down)
├── {Timestamp}_{Name}.Designer.cs     ← model snapshot tại thời điểm migration
└── ApplicationDbContextModelSnapshot.cs  ← current model state (được overwrite mỗi migration)

Gotcha #17: Thiếu ModelSnapshot.cs → migrations add kế tiếp sẽ sinh duplicate columns. Thiếu Designer.cs → không revert được.

Pitfalls thường gặp

P1 — DesignTime DbContext resolve fail

Triệu chứng: dotnet ef migrations add → Unable to resolve service for type 'DbContextOptions<ApplicationDbContext>'.

Nguyên nhân: EF tooling chạy đứng ngoài runtime DI, cần factory riêng.

Fix: Đã có src/Backend/SolutionErp.Infrastructure/Persistence/DesignTimeDbContextFactory.cs. Nếu connection string thay đổi → update factory, không chỉ appsettings.json.

P2 — Table rename / column rename gen ra DROP + CREATE

Triệu chứng: Migration sinh DropColumn + AddColumn thay vì RenameColumn → mất data.

Fix: Sửa migration thủ công sang migrationBuilder.RenameColumn(...). Hoặc dùng [Column("newname")] attribute để EF tự detect rename.

P3 — Query filter (soft delete) khi thêm FK

Triệu chứng: Warning The entity type 'X' has a global query filter but referencing entity 'Y' doesn't. This may lead to inconsistent results.

Fix: Entity reference cũng phải có query filter:

builder.HasQueryFilter(x => !x.IsDeleted);

Hoặc dùng .IgnoreQueryFilters() cho query cần bypass.

P4 — FK cascade/restrict khác với expectation

Triệu chứng: Migration apply OK nhưng DELETE parent → cascade sang child (hoặc ngược lại restrict block).

Fix: Explicit config trong IEntityTypeConfiguration<T>:

builder.HasOne(x => x.Contract)
    .WithMany(c => c.Approvals)
    .HasForeignKey(x => x.ContractId)
    .OnDelete(DeleteBehavior.Cascade);  // hoặc Restrict, SetNull

Case study quan trọng: Contracts.WorkflowDefinitionId → WorkflowDefinitions.Id PHẢI dùng Restrict để protect HĐ cũ khi admin archive version (xem workflow-contract.md invariants).

P5 — Nullable reference type gen column NOT NULL

Triệu chứng: Property public string? Description → migration gen NOT NULL.

Fix: Check builder.HasQueryFilter chỗ config, hoặc explicit builder.Property(x => x.Description).IsRequired(false).

P6 — AddVersionedWorkflows duplicate seed

Case study hiện tại: Nếu thêm migration mới sau AddVersionedWorkflows, cẩn thận KHÔNG trigger DbInitializer.SeedWorkflowDefinitionsAsync 2 lần. Check if (!db.WorkflowDefinitions.Any()) trong DbInitializer.

Workflow khi thêm entity mới (example: add AuditLog)

1. Domain/AuditLogs/AuditLog.cs — tạo entity (BaseEntity hoặc AuditableEntity)
2. Infrastructure/Persistence/Configurations/AuditLogConfiguration.cs
   - ToTable("AuditLogs")
   - Unique index trên (EntityType, EntityId) nếu cần
3. Infrastructure/Persistence/ApplicationDbContext.cs
   - public DbSet<AuditLog> AuditLogs => Set<AuditLog>();
4. Application/Common/Interfaces/IApplicationDbContext.cs
   - DbSet<AuditLog> AuditLogs { get; }
5. dotnet ef migrations add AddAuditLogs
6. Review file .cs sinh ra → OK
7. dotnet ef database update → LocalDB apply
8. Test: dotnet run → check bảng được tạo
9. Commit [CLAUDE] Domain+Infra: add AuditLog entity + migration
10. ⚠️ UPDATE docs/database/schema-diagram.md (ERD + migration table)
11. UPDATE docs/STATUS.md nếu là work lớn

Apply prod (VPS)

# Trên VPS, sau khi deploy code:
# Option 1: auto migrate — DbInitializer.MigrateAsync() chạy khi API startup
# Option 2: manual script
dotnet ef migrations script <LastApplied> --idempotent --output migrate.sql
# Review migrate.sql → chạy qua sqlcmd:
sqlcmd -S .\SQLEXPRESS -d SolutionErp -U vrapp -P <pw> -i migrate.sql

Prod safety:

• Backup trước: scripts/backup-sql.ps1
• Dry-run idempotent script local trước
• Test rollback plan: script from-N-to-M-1 sẵn

Code pointers

• src/Backend/SolutionErp.Infrastructure/Persistence/ApplicationDbContext.cs — DbSet cho 91 bảng (42 migration)
• src/Backend/SolutionErp.Infrastructure/Persistence/DesignTimeDbContextFactory.cs — EF tooling factory
• src/Backend/SolutionErp.Infrastructure/Persistence/DbInitializer.cs — seed + warn + migrate runtime + backfill (idempotent reconcile pattern)
• src/Backend/SolutionErp.Infrastructure/Persistence/Configurations/ — IEntityTypeConfiguration per entity
• src/Backend/SolutionErp.Application/Common/Interfaces/IApplicationDbContext.cs — interface Application layer

Related

• docs/database/database-guide.md — conventions + migration workflow chi tiết
• docs/database/schema-diagram.md — ERD 91 bảng + §11 PE + §12 Budget + §13 PEDeptOpinions (Mig 15) + §14 ApprovalWorkflow V2 (Mig 22-25) + §15 PE Level Opinions V2 (Mig 26); §16+ Mig 27-42 detail pending (xem migration table)
• docs/gotchas.md #7, #17, #38 — migration pitfalls + Identity 4-field rename