Async local storage example as CLS replacement

[marleystipich2]

Summary by Sourcery

Migrate the request-scoped context implementation from express-http-context/CLS to Node.js AsyncLocalStorage while keeping the existing cls API surface intact.

Enhancements:

• Replace express-http-context, cls-bluebird, and Sequelize CLS usage with an AsyncLocalStorage-based implementation that preserves the existing middleware and getReq interface.
• Simplify cls.patchMiddleware now that AsyncLocalStorage automatically propagates context without manual binding.
• Remove express-http-context usage from the main routing setup in favor of the new AsyncLocalStorage-backed cls middleware.

Documentation:

• Add a detailed AsyncLocalStorage migration guide explaining the rationale, required code changes, and verification steps.

[sourcery-ai]

Reviewer's Guide

Replaces the custom CLS/express-http-context-based request context handling with Node.js AsyncLocalStorage, removes related middleware wiring, and adds a migration guide documenting the change and its rationale.

Sequence diagram for AsyncLocalStorage-based request context access

sequenceDiagram
    actor Client
    participant ExpressApp
    participant CLSMiddleware
    participant RouteHandler
    participant CLSUtil
    participant AsyncLocalStorage

    Client->>ExpressApp: HTTP request
    ExpressApp->>CLSMiddleware: middleware(req, res, next)
    CLSMiddleware->>AsyncLocalStorage: run({ req }, next)
    activate AsyncLocalStorage
    AsyncLocalStorage-->>RouteHandler: invoke next within context
    deactivate AsyncLocalStorage

    RouteHandler->>CLSUtil: getReq()
    CLSUtil->>AsyncLocalStorage: getStore()
    AsyncLocalStorage-->>CLSUtil: { req }
    CLSUtil-->>RouteHandler: req
    RouteHandler-->>Client: HTTP response

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File-Level Changes

Change	Details	Files
Replace express-http-context/CLS integration with AsyncLocalStorage-based request storage.	Remove express-http-context, cls-bluebird, Bluebird, and Sequelize CLS initialization from the CLS utility module. Introduce a shared AsyncLocalStorage instance and use it in the CLS middleware to wrap each request with a context object containing req. Update getReq helper to read req from the AsyncLocalStorage store and handle missing context safely. Simplify patchMiddleware to return the original middleware function without manual binding since AsyncLocalStorage propagates context automatically.	src/util/cls.js
Align routing setup with new CLS implementation and drop express-http-context middleware.	Remove express-http-context import from the routes setup. Stop registering express-http-context middleware while keeping cls.middleware in the Express app pipeline.	src/routes.js
Add documentation describing the AsyncLocalStorage migration and its impact.	Create a detailed migration guide explaining the switch from cls-hooked/express-http-context to AsyncLocalStorage, including code before/after, rationale, transactional behavior analysis, and testing steps. Document optional package.json cleanup to remove now-unused CLS-related dependencies in a follow-up change.	ASYNC_LOCAL_STORAGE_MIGRATION.md

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