Refactor: pass adminApiMiddleware into createKoaApp(); rename koaMiddleware to routesMiddleware

[Copilot]

Summary

adminApiMiddleware was being constructed inside createKoaApp(), coupling middleware lifecycle to the factory and making parallel server setups awkward. This moves construction to the caller and renames the ambiguous koaMiddleware to routesMiddleware throughout. The registry parameter has also been removed from createKoaApp() as it was only used for a debug log line that has been dropped.

Before:

// createKoaApp internally constructed adminApiMiddleware
const koaApp = createKoaApp(registry, middleware, config, contextRegistry);
// returned: { koaMiddleware: middleware, ... }

After:

const adminMiddleware = config.startAdminApi
  ? adminApiMiddleware(registry, contextRegistry, config)
  : undefined;
const koaApp = createKoaApp(middleware, config, adminMiddleware);
// returned: { routesMiddleware: middleware, ... }

Original Prompt

adminApiMiddleware should not be constructed inside createKoaApp(). That's making the parallel servers implementation difficult.

Also change the name of koaMiddleware to routesMiddleware.

Manual acceptance tests

• Starting with startAdminApi: true still serves admin API routes at /_counterfact/api/health
• Starting with startAdminApi: false results in no admin API routes being mounted
• The routesMiddleware property returned from counterfact() is a callable Koa middleware function
• Existing API routes (e.g. GET /pets) respond correctly after the refactor
• Swagger UI at /counterfact/swagger still loads correctly

Tasks

• Renamed koaMiddleware → routesMiddleware in src/server/koa-middleware.ts (export) and all callsites
• Removed ContextRegistry param from createKoaApp(); replaced with optional adminApiMiddleware?: Koa.Middleware
• Removed registry param from createKoaApp() and dropped the debug("routes", registry.routes) line that was its only use
• Moved adminApiMiddleware construction + startAdminApi guard into src/app.ts (the caller)
• Updated returned object property koaMiddleware → routesMiddleware in counterfact()
• Updated docs, tests, and added changeset

[pmcelhaney]

Remove this line and remove registry from the arguments

[Copilot]

Done in 3b56164. Removed debug("routes", registry.routes) and the registry parameter from createKoaApp().