[Knowledge] web-app: ## Advisory Notes — Stage 1: Managed Identity - **[Stabilit...

## Knowledge Contribution

**Type:** New service
**File:** `knowledge/services/web-app.md`
**Status:** NEW FILE — this knowledge file does not exist yet and must be created

### Context
## Advisory Notes — Stage 1: Managed Identity

- **[Stability]** The identity module uses API version `2023-07-31-preview`; preview APIs may introduce breaking changes or be retired — consider pinning to the GA version `2023-01-31` for production deployments.

- **[Security]** Deployment outputs (client ID, principal ID) are written to a local JSON file with no access controls; in CI/CD pipelines, prefer storing these in a Key Vault or using deployment output references directly to avoid credent

### Rationale
## Advisory Notes — Stage 1: Managed Identity

- **[Stability]** The identity module uses API version `2023-07-31-preview`; preview APIs may introduce breaking changes or be retired — consider pinning to the GA version `2023-01-31` for production deployments.

- **[Security]** Deployment outputs (client ID, principal ID) are written to a local JSON file with no access controls; in CI/CD pipelines, prefer storing these in a Key Vault or using deployment output references directly to avoid credent

### Content to Add
```
## Advisory Notes — Stage 1: Managed Identity

- **[Stability]** The identity module uses API version `2023-07-31-preview`; preview APIs may introduce breaking changes or be retired — consider pinning
```

### Source
Build advisory review

### Required Knowledge File Sections
The new knowledge file MUST include ALL of these sections:
1. **Description** (one-line summary)
2. **When to Use** (scenarios and selection criteria)
3. **POC Defaults** (default SKU, tier, configuration)
4. **Terraform Patterns** (azapi_resource with RBAC)
5. **Bicep Patterns** (ARM template resources)
6. **Application Code** (Python, C#, Node.js — where applicable)
7. **Common Pitfalls** (deployment failures, misconfigurations)
8. **Production Backlog Items** (what changes for production)

Create knowledge/services/web-app.md and start by reviewing the Managed Identity advisory notes and the listed source, including the API-version and deployment-output concerns. Structure the file with all eight required sections, covering Terraform azapi_resource with RBAC, Bicep patterns, and applicable Python, C#, and Node.js examples. Done means every required section is present and the stated POC and production guidance is documented.

Written by the indexing model from the issue text.