refactor(core): enhance HttpKernel pipeline and matcher system with full context and error handling

BREAKING CHANGE: `parseQuery` utility removed; `IRouteMatcher` now includes query parsing; `RouteBuilder.middleware` and `handle` are now strictly typed per builder instance.

- Add `isHandler` and `isMiddleware` runtime type guards for validation in `HttpKernel`.
- Introduce `createEmptyContext` for constructing default context objects.
- Support custom HTTP error handlers (`404`, `500`) via `IHttpKernelConfig.httpErrorHandlers`.
- Default error handlers return meaningful HTTP status text (e.g., "Not Found").
- Replace legacy `parseQuery` logic with integrated query extraction via `createRouteMatcher`.

- Strongly type `RouteBuilder.middleware()` and `.handle()` methods without generic overrides.
- Simplify `HttpKernel.handle()` and `executePipeline()` through precise control flow and validation.
- Remove deprecated `registerRoute.ts` and `HttpKernelConfig.ts` in favor of colocated type exports.

- Add tests for integrated query parsing in `createRouteMatcher`.
- Improve error handling tests: middleware/handler validation, double `next()` call, thrown exceptions.
- Replace `assertRejects` with plain response code checks (via updated error handling).

- Removed `parseQuery.ts` and all related tests — query parsing is now built into route matching.
- `IRouteMatcher` signature changed to return `{ params, query }` instead of only `params`.
- `HttpKernelConfig` now uses `DeepPartial` and includes `httpErrorHandlers`.
- `RouteBuilder`'s generics are simplified for better DX and improved type safety.

This refactor improves clarity, test coverage, and runtime safety of the request lifecycle while reducing boilerplate and eliminating duplicated query handling logic.

Signed-off-by: Max P. <Mail@MPassarello.de>

src/RouteBuilder.ts

@@ -41,13 +41,13 @@ export class RouteBuilder<TContext extends IContext = IContext>
      * @param mw - A middleware function to be executed before the handler.
      * @returns A new `RouteBuilder` instance for continued chaining.
      */
-    middleware<_TContext extends IContext = TContext>(
-        mw: IMiddleware<_TContext>,
-    ): IRouteBuilder<_TContext> {
-        return new RouteBuilder<_TContext>(
-            this.registerRoute as unknown as RegisterRoute<_TContext>,
+    middleware(
+        mw: IMiddleware<TContext>,
+    ): IRouteBuilder<TContext> {
+        return new RouteBuilder<TContext>(
+            this.registerRoute,
             this.def,
-            [...this.mws as unknown as IMiddleware<_TContext>[], mw],
+            [...this.mws, mw],
         );
     }
 
@@ -59,15 +59,15 @@ export class RouteBuilder<TContext extends IContext = IContext>
      *
      * @param handler - The final request handler for this route.
      */
-    handle<_TContext extends IContext = TContext>(
-        handler: IHandler<_TContext>,
+    handle(
+        handler: IHandler<TContext>,
     ): void {
         const matcher = this.matcherFactory(this.def);
         this.registerRoute({
             method: this.def.method,
             matcher,
             middlewares: this.mws,
-            handler: handler as unknown as IHandler<TContext>,
+            handler: handler,
         });
     }
 }