# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## Project Overview

**K-ArtSell Aegis v16.0** is a complex financial/investment advisory system built on a **Modular Monolith** with **Vertical Slice** architecture. It enforces strict execution completeness, evidence preservation, and controlled model operations—not production-ready until all validation gates (252+ trading days shadow, OOS testing, PBO/DSR verification) pass.

**Status:** `IMPLEMENTATION_TEMPLATE / STATIC_VALIDATED / BUILD_DB_E2E_SHADOW_REHEARSAL_REQUIRED`

## Quick Start

### Prerequisites
- .NET 10 SDK
- Node.js 22 / pnpm 10
- PostgreSQL 17 (installed locally)

### Local PostgreSQL Setup

Ensure PostgreSQL 17 is running locally on default port 5432. Create the database and user:

```sql
CREATE DATABASE kartsell;
CREATE USER kartsell WITH PASSWORD 'kartsell';
ALTER ROLE kartsell CREATEDB;
GRANT ALL PRIVILEGES ON DATABASE kartsell TO kartsell;
```

### Local Development Environment

```bash
# Backend: restore, build, migrate, test
dotnet restore KArtSell.sln
dotnet build KArtSell.sln -c Release
dotnet run --project src/KArtSell.DbMigrator -c Release

# Run backend tests
dotnet test KArtSell.sln -c Release --logger trx

# Run a single test
dotnet test --filter "FullyQualifiedName=MyNamespace.MyTest.TestMethod" -c Release

# Frontend: install, typecheck, test, build
cd frontend
pnpm install --frozen-lockfile
pnpm typecheck
pnpm test
pnpm build

# Run frontend E2E tests
pnpm exec playwright install --with-deps chromium
pnpm e2e

# Run dev server (watch mode, hot reload)
pnpm dev  # Backend in another terminal
```

### Database Connection
```
Host: localhost
Port: 5432
Database: kartsell
User: kartsell
Password: kartsell
```

Environment variable: `KARTSELL_POSTGRES=Host=localhost;Port=5432;Database=kartsell;Username=kartsell;Password=kartsell`

**On Windows (PowerShell):**
```powershell
$env:KARTSELL_POSTGRES="Host=localhost;Port=5432;Database=kartsell;Username=kartsell;Password=kartsell"
```

**On macOS/Linux (bash):**
```bash
export KARTSELL_POSTGRES="Host=localhost;Port=5432;Database=kartsell;Username=kartsell;Password=kartsell"
```

## Architecture

### Backend: Modular Monolith + Vertical Slices

#### Module Structure
```
src/
  KArtSell.Host/                    # Main ASP.NET Core app
  KArtSell.BuildingBlocks/          # Shared infrastructure (logging, serialization, extensions)
  KArtSell.DbMigrator/              # DbUp migrations
  KArtSell.Modules.ModelOperations/ # Model lifecycle, validation, activation
  KArtSell.Modules.SignalEngine/    # Trading signal generation
```

#### Vertical Slice Template
Each feature is a complete, self-contained slice from HTTP endpoint to database, located under `Features/<SliceName>/`:

```
Features/<SliceName>/
  Endpoint.cs         # FastEndpoints route handler (HTTP/contract/status codes)
  Request.cs          # Input model with validation via Zod-like pattern
  Response.cs         # Output model (DTO)
  Validator.cs        # Fluent/Policy validation rules
  Handler.cs          # Use case orchestration (Application layer)
  Policy.cs           # Pure business decision logic (Domain layer)
  Sql.cs              # Dapper queries (Data layer)
  Mapper.cs           # Entity ↔ DTO mapping
  Jobs/               # Related Hangfire jobs
  Contracts/          # Event/Job contract definitions
  Tests/              # Unit/integration tests specific to this slice
  README.md           # Traceability: requirements, ADRs, assumptions
```

**Key rule:** Endpoint handles HTTP concerns (routing, negotiation); Handler handles transaction boundaries; Policy makes decisions; Sql uses Dapper for explicit, schema-qualified queries.

#### Design Principles
- **No Generic Repository:** Each slice writes its own Dapper queries; promotes clarity.
- **No Service Layer:** Handler + Policy + Sql replaces it; keeps flow visible.
- **Module Isolation:** Modules do not query each other's source tables directly.
  - Synchronous: Use narrow Read Port services.
  - Asynchronous: Use Outbox/Inbox event patterns.
- **PIT (Point-in-Time) Queries:** Must include `WHERE published_at <= cutoff` and revision resolver.
- **Evidence & Audit:** Update/delete are blocked; new state appended as new revision.
- **Migrations:** `src/KArtSell.DbMigrator` uses DbUp; file naming: `NNNN_description.sql`. Each module has ordered, checksummed migrations.

### Frontend: Vue 3 + Vite + Modular Feature Structure

#### Directory Layout
```
frontend/src/
  app/                # Core app initialization, routing, config
  features/           # Feature modules (one per business capability)
    <feature>/
      components/     # Scoped to this feature
      pages/          # Route-level pages
      stores/         # Pinia stores (state management)
      composables/    # Reusable logic (Vue 3 hooks)
      types/          # TS interfaces for this feature
  shared/
    ui/
      adapter/        # PrimeVue/AG Grid wrappers (mandatory boundary)
      components/     # Common components (QueryStateBoundary, PermissionGuard, CrudForm, etc.)
      layouts/        # Page layout templates
    crud/             # Generic CRUD form logic
    composables/      # Global composables (useFetch, useAuth, etc.)
    types/            # Global types, contracts
    stores/           # Global Pinia stores (auth, user, preferences)
  design-system/      # Design tokens, typography, color scales (PrimeVue theme overrides)
```

#### State Management Rules
| State | Owner | Tool |
|-------|-------|------|
| API responses, cache, stale, retry | TanStack Query | @tanstack/vue-query |
| Session, role, UI preferences | Global store | Pinia |
| Form values, errors, touched | Form library | vee-validate + Zod |
| URL filters, pagination, sorting | Router | vue-router query/params |
| Large data tables, virtual scroll | Server-side row model | AG Grid server mode |

**Anti-patterns:**
- Do NOT duplicate API responses in Pinia.
- Do NOT write 401/409/422/429/503 error handling in every screen.
- Do NOT manage query cache manually; let TanStack Query handle it.

#### Component Elevation Criteria
Promote to `shared/ui/components/` only when:
1. **Same business meaning & permissions** (not just visual similarity).
2. **Repeated state/error handling logic** across 3+ consumers.
3. **Accessibility & testing** already fully implemented.

**Always-shared components:**
- `QueryStateBoundary` (loading/error/empty states)
- `PermissionGuard` (RBAC enforcement)
- `CrudForm` (standard CRUD form)
- `VersionConflictDialog` (optimistic concurrency)
- `DataFreshnessBadge` (cache/stale indicators)
- `DataGridShell` (AG Grid wrapper with sorting, filtering, export)

### Database & Migrations

#### DbUp
- **Run at startup:** `KArtSell.DbMigrator` is the single source of truth.
- **Schema ownership:** Each module owns its schema (e.g., `model_operations.*`, `signal_engine.*`).
- **Safety:** Migrations are idempotent and checksummed; failed migration rolls back and waits for manual intervention.
- **Test:** Each migration has fresh/upgrade/re-run/failure-recovery tests in CI.

#### Query Patterns
```csharp
// DO: Schema-qualified, explicit columns, cancellation token
const string sql = """
  SELECT id, name, created_at
  FROM model_operations.signals
  WHERE published_at <= @cutoff
    AND status = @status
  ORDER BY created_at DESC
""";

// DON'T: SELECT *, generic repository, no token
const string sql = "SELECT * FROM signals WHERE status = @status";
```

#### Async Coupling: Outbox/Inbox
- **Outbox:** When a command succeeds, events are inserted into `outbox` in the same transaction.
- **Inbox:** A Hangfire job polls the outbox, publishes events, and marks them as processed.
- **Idempotency:** Each inbox handler is idempotent; replayed events are no-ops.

### Hangfire (Background Jobs & Scheduling)

#### Job Design
- **Not a business decision maker:** Hangfire executes approved Application Commands, not policies.
- **Idempotency key:** Each job must be replayable without side effects.
- **Watermark & version set:** Track input/output state across retries.
- **Queue isolation:** `q-customer-sla` (business SLA) is separate from `q-research` (non-critical).
- **Retry classification:**
  - `transient` (network glitch, retry immediately)
  - `permanent` (bad input, log & alert)
  - `dq` (data quality issue, quarantine for manual review)
  - `business-hold` (awaiting approval or external event)

#### Example Job Structure
```csharp
public class MyJobCommand : ICommand
{
    public string IdempotencyKey { get; set; }
    public Guid JobRunId { get; set; }
    public Guid CorrelationId { get; set; }
}
```

Jobs do not call other jobs directly; instead, they emit events or check readiness gates.

### SignalR (Real-Time Push)

Used for live notifications (model activation events, approval notifications). Follows Hub/Group pattern with correlation to `CorrelationId` for traceability.

## Testing Strategy

### xUnit Backend Tests

#### Test Organization
```
tests/
  KArtSell.ArchitectureTests/       # Compile-time architecture rules
  KArtSell.ModelOperations.UnitTests/
  KArtSell.SignalEngine.UnitTests/
  KArtSell.Integration.Tests/       # E2E with real DB (if exists)
```

#### Test Levels
1. **Unit:** Pure functions (Policy, Mapper), no I/O. Fast, deterministic.
2. **Integration:** Handler + Dapper + real PostgreSQL. Validates transaction boundaries, Outbox/Inbox.
3. **Data:** SQL query validation, schema conformance, index effectiveness.
4. **E2E:** Full HTTP stack; used sparingly for critical paths.
5. **Golden/Frozen OOS:** Before merging algorithm changes, lock baseline and diff against new run.

#### Run Tests
```bash
dotnet test KArtSell.sln -c Release
dotnet test --filter "Category=Integration" -c Release
dotnet test --filter "FullyQualifiedName~UnitTests" -c Release --verbosity quiet
```

### Vitest Frontend Tests

```bash
cd frontend
pnpm test                           # Run all tests
pnpm test -- --reporter=verbose     # Verbose output
pnpm test -- <test-file-pattern>    # Run subset
pnpm test -- --coverage             # Coverage report
```

### Playwright E2E

```bash
cd frontend
pnpm e2e                            # Run all E2E tests headless
pnpm e2e -- --debug                 # Debug mode (browser stays open)
pnpm exec playwright test --headed  # Run with browser UI
```

## Observability

### Logging
- **Tool:** Serilog with structured properties.
- **Correlation:** All logs are tagged with `CorrelationId`, `JobRunId`, `EvidenceId`.
- **Sensitive data:** PII, tokens, API keys are NEVER logged (use redaction middleware).
- **Levels:** INFO (user actions), DEBUG (internal flow), WARN (recoverable issues), ERROR (unrecoverable, alert required).

### Tracing & Metrics
- **Tool:** OpenTelemetry for distributed tracing and metrics.
- **Spans:** HTTP requests, database queries, job execution, event processing.
- **Alerts:** Send to Telegram integration (configured in `KArtSell.Host` startup).

### Operational Dashboards (Priority Order)
1. **Batch SLA:** Job completion times, queue depths (q-customer-sla vs q-research).
2. **Data Quality Quarantine:** Jobs marked `dq` by retry classifier.
3. **Duplicate Detection:** Outbox duplicate events.
4. **Reconciliation Breaks:** Mismatch between expected and actual state (Evidence vs current).
5. **Model Drift:** OOS (out-of-sample) performance metrics.

## Common Workflows

### Adding a New Vertical Slice

1. **Scaffold the structure:**
   ```bash
   python tools/scaffold_vertical_slice.py --name MyFeature --module ModelOperations
   ```

2. **Define the contract** (before code):
   - Request/Response DTOs in `Contracts/`
   - Event schema in `Contracts/Events/` if async coupling needed
   - Validation rules (vee-validate schema on FE, Fluent on BE)

3. **Implement backend slice:**
   - `Handler.cs`: Orchestration, transaction handling
   - `Policy.cs`: Pure business logic
   - `Sql.cs`: Dapper queries (schema-qualified, no SELECT *)
   - `Endpoint.cs`: HTTP routing & status codes
   - `README.md`: Traceability link to requirement/ADR

4. **Write tests:**
   - Unit: Policy, Mapper logic
   - Integration: Handler + Dapper + real DB
   - Verify Outbox events are created if async

5. **Implement frontend feature:**
   - Feature module under `features/<feature>/`
   - Use `features/<feature>/pages/` for route-level components
   - Use `shared/ui/adapter/` for any UI component usage
   - Form validation with vee-validate + Zod schema from BE contract

6. **Validation gates (pre-merge):**
   - Architecture tests pass
   - DB migration is idempotent (fresh/upgrade test)
   - No SELECT *, no direct cross-module queries
   - Outbox/Inbox tests if async
   - Frontend typecheck + test + build
   - E2E smoke test (if user-facing)

### Refactoring (Characterized, Isolated, Verified)

1. **Characterize:** Lock current behavior with tests + perf baseline + Golden data.
2. **Isolate:** Separate I/O (Dapper queries, HTTP) from logic (Policy).
3. **Transform:** One small change at a time (rename, extract, move).
4. **Verify:** All tests pass, no perf regression, backtest algorithm changes against Golden.
5. **Simplify:** Delete dead abstractions, feature flags, branches.
6. **Observe:** Post-release SLO/DQ/model drift monitoring.
7. **Close Debt:** Update Debt ID, leave ADR for future maintainers.

### Creating a Background Job

1. **Define the command:**
   ```csharp
   public class MyJobCommand : ICommand
   {
       public Guid IdempotencyKey { get; set; }
       public Guid CorrelationId { get; set; }
       public string InputData { get; set; }
   }
   ```

2. **Implement the handler:**
   - Idempotent: Re-run should be safe and produce same result.
   - Classify failures: transient/permanent/dq/business-hold.
   - Emit events to Outbox for async notifications.

3. **Schedule via Hangfire:**
   ```csharp
   await backgroundJobClient.EnqueueAsync<MyJobHandler>(h => h.Handle(command));
   ```

4. **Test retry & replay scenarios:**
   - Job runs successfully.
   - Job fails and is retried (verify idempotency).
   - Job is replayed from cold state (verify determinism).

## Guardrails & Anti-Patterns

### Coding Standards (from VIBE_CODING_GUARDRAILS.md)

**Before requesting code changes, ensure these 8 inputs are present:**
1. **Source:** Reference policy, ADR, data contract, requirement ID
2. **Slice Spec:** User goal, non-goal, state transitions, RBAC
3. **Screen Spec:** Component tree, state management, a11y
4. **Contract:** Endpoint paths, event schemas, HTTP status codes, ETag/idempotency handling
5. **Data:** Schema, columns, PIT conditions, migration, index plan
6. **Tests:** Unit/integration/data/E2E/Golden scenarios + failure cases
7. **Ops:** Metrics, alerts, runbooks, rollback procedure, on-call owner
8. **Output Rule:** Changed files, commands to verify, assumptions, residual risks

### Blocking Rules
- **No undocumented policy IDs or thresholds.** Every numeric constant must trace to a requirement.
- **Pending decisions:** Mark with `DECISION_REQUIRED` or `DESIGN_PROPOSAL` comment.
- **One PR = one slice or one refactoring goal.** No mixing feature work + unrelated cleanup.
- **Feature changes ≠ refactoring.** Separate PRs: feature, then refactoring, then verify.
- **Never hide failing/skipped tests.** If a test fails, fix it or raise an issue.
- **SQL review:** Generated SQL must pass schema owner review, PIT validation, index analysis.
- **Algorithm changes:** Never merge without Golden/Frozen OOS diff showing no regression.
- **Real customer data:** Never include in prompts, fixtures, or logs.

### Model Operations Specifics
- **Model lifecycle:** Freeze → Mature → Score → Diagnose → Hypothesis → Challenger → Validate → Review → Manual Activation. No auto-learning, auto-promotion, or auto-ordering.
- **Sell priority:** `HARD_IMPAIRMENT → PORTFOLIO_SURVIVAL → DYNAMIC_PROFIT_FLOOR → CONCENTRATION/LIQUIDITY → OPPORTUNITY_COST → REENTRY_OPTION` (immutable).
- **Non-value-loss sell:** Requires ReentryWatch, new CycleId/Lot, step intervals, expiry, dedup.
- **Activation gating:** Every model activation requires ModelCard, OOS/PBO/DSR evidence, maker-checker approval, effective_at timestamp, rollback justification.

## Tools & Scripts

### Scaffolding
```bash
python tools/scaffold_vertical_slice.py --name MyFeature --module ModelOperations
python tools/scaffold_ui_screen.py --name MyScreen --feature MyFeature
```

### Validation
```bash
python tools/validate_v16.py          # Full v16 validation (contracts, migrations, Python tests)
python -m unittest discover           # Run all Python unit tests
```

### FastEndpoints
- Docs: [FastEndpoints GitHub](https://github.com/FastEndpoints/FastEndpoints)
- Pattern: Each endpoint maps to a Vertical Slice; routes are discovered automatically.

## Documentation & Resources

### Key Documents
- `docs/03_ARCHITECTURE_BE_FE.md` — Modular Monolith, Vertical Slice, Dapper, Hangfire, FE state ownership rules.
- `docs/06_VIBE_CODING_GUARDRAILS.md` — AI input packets, blocking rules, refactoring methodology.
- `contracts/ui/ui-adapter.v3.json` — FE adapter contract (PrimeVue/AG Grid wrapper boundaries).
- `contracts/schedules/model-operations.v3.json` — Job scheduling contract.
- `README.md` — Project status, v16 delta, validation gates.

### Contracts Directory
```
contracts/
  ui/               # Frontend adapter & component contracts
  schedules/        # Job scheduling contracts
  data/             # Domain data models (PIT envelope, projection)
  events/           # Async event schemas
  metrics/          # Outcome metrics schema
```

## Validation Gates (Not Yet Passed)

Do NOT claim production readiness until:
- `.NET 10 restore/build/test` on CI passes consistently
- `pnpm frozen install/typecheck/Vitest/build/Playwright` on CI passes
- PostgreSQL DbUp fresh/upgrade/re-run/failure-recovery tests pass
- Outbox/Inbox crash-recovery & audit reconciliation rehearsal passes
- 252+ trading-day shadow run with OOS at multiple market phases
- PBO (probability of backtest overfit) and DSR (daily sharpe ratio) evidence

Before all gates pass: **No production deployment, no advisory-with-automation, no auto-ordering, no auto-model-promotion.**