feat: implement JIT compilation output for transformAngularFile (#98)

* feat: implement JIT compilation output for transformAngularFile

When `jit: true` is passed, the compiler now produces Angular JIT-compatible
output instead of AOT-compiled code. This matches the output format of
Angular CLI's JitCompilation class:

- Decorator downleveling via `__decorate` from tslib
- templateUrl/styleUrl replaced with `angular:jit:template:file;` imports
- Constructor params emitted as `static ctorParameters` for runtime DI
- Class restructured to `let X = class X {}; X = __decorate([...], X);`
- Templates are NOT compiled (runtime JIT compiler handles that)
- Import elision disabled (ctor param types needed at runtime)

Closes #97

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: JIT transform correctly downlevels member decorators and union types

Fixes two bugs identified in code review:

1. (High) Member decorators (@input, @output, @HostBinding, etc.) were
   removed from class bodies without being emitted as `static propDecorators`.
   Angular's JIT runtime reads `propDecorators` to discover inputs/outputs/
   queries at runtime — without it, data binding silently breaks. Now emits:
     static propDecorators = {
       myInput: [{ type: Input }],
       myOutput: [{ type: Output }],
     };

2. (Medium) `extract_type_name_from_annotation` only skipped TSNullKeyword
   in union types. For `undefined | T` or `null | undefined | T`, the function
   encountered TSUndefinedKeyword first, immediately recursed and returned None,
   never reaching the actual type. Fixed to try each union member and return
   the first resolvable name.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix(jit): align union type resolution with Angular's typeReferenceToExpression

Angular's reference filters only `null` literal types from union types
and requires exactly one non-null type to remain. Previously we iterated
all union members and returned the first resolvable one, which is more
permissive than Angular's behavior.

With Angular-aligned semantics:
- `T | null` → resolves to T (1 non-null type remains)
- `undefined | T` → unresolvable (2 non-null types remain)
- `null | undefined | T` → unresolvable (2 non-null types remain)

Unresolvable types emit `{ type: undefined }` matching Angular's
`paramType || ts.factory.createIdentifier('undefined')` fallback.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: Brooooooklyn

crates/oxc_angular_compiler/src/component/transform.rs

@@ -0,0 +1,17 @@
+---
+source: crates/oxc_angular_compiler/tests/integration_test.rs
+expression: result.code
+---
+import { Component } from '@angular/core';
+import { __decorate } from "tslib";
+
+let AppComponent = class AppComponent {
+    title = 'app';
+};
+AppComponent = __decorate([
+    Component({
+    selector: 'app-root',
+    template: '<h1>Hello</h1>',
+})
+], AppComponent);
+export { AppComponent };

crates/oxc_angular_compiler/tests/integration_test.rs

@@ -0,0 +1,22 @@
+---
+source: crates/oxc_angular_compiler/tests/integration_test.rs
+expression: result.code
+---
+import { Component } from '@angular/core';
+import { TitleService } from './title.service';
+import { __decorate } from "tslib";
+
+let AppComponent = class AppComponent {
+    constructor(private titleService: TitleService) {}
+
+static ctorParameters = () => [
+    { type: TitleService }
+];
+};
+AppComponent = __decorate([
+    Component({
+    selector: 'app-root',
+    template: '<h1>Hello</h1>',
+})
+], AppComponent);
+export { AppComponent };

crates/oxc_angular_compiler/tests/snapshots/integration_test__jit_class_restructuring.snap

@@ -0,0 +1,21 @@
+---
+source: crates/oxc_angular_compiler/tests/integration_test.rs
+expression: result.code
+---
+import { Directive, Input } from '@angular/core';
+import { __decorate } from "tslib";
+
+let HighlightDirective = class HighlightDirective {
+    color: string = 'yellow';
+
+static propDecorators = {
+    color: [{ type: Input }]
+};
+};
+HighlightDirective = __decorate([
+    Directive({
+    selector: '[appHighlight]',
+    standalone: true,
+})
+], HighlightDirective);
+export { HighlightDirective };

crates/oxc_angular_compiler/tests/snapshots/integration_test__jit_constructor_deps.snap

@@ -0,0 +1,33 @@
+---
+source: crates/oxc_angular_compiler/tests/integration_test.rs
+expression: result.code
+---
+import { Component, signal } from '@angular/core';
+import { RouterOutlet } from '@angular/router';
+import { Lib1 } from 'lib1';
+import { TitleService } from './title.service';
+import { __decorate } from "tslib";
+import __NG_CLI_RESOURCE__0 from "angular:jit:template:file;./app.html";
+import __NG_CLI_RESOURCE__1 from "angular:jit:style:file;./app.css";
+
+let App = class App {
+    titleService;
+    title = signal('app');
+    constructor(titleService: TitleService) {
+        this.titleService = titleService;
+        this.title.set(this.titleService.getTitle());
+    }
+
+static ctorParameters = () => [
+    { type: TitleService }
+];
+};
+App = __decorate([
+    Component({
+    selector: 'app-root',
+    imports: [RouterOutlet, Lib1],
+    template: __NG_CLI_RESOURCE__0,
+    styles: [__NG_CLI_RESOURCE__1],
+})
+], App);
+export { App };

crates/oxc_angular_compiler/tests/snapshots/integration_test__jit_directive.snap

@@ -0,0 +1,16 @@
+---
+source: crates/oxc_angular_compiler/tests/integration_test.rs
+expression: result.code
+---
+import { Component } from '@angular/core';
+import { __decorate } from "tslib";
+
+let AppComponent = class AppComponent {};
+AppComponent = __decorate([
+    Component({
+    selector: 'app-root',
+    template: '<h1>Hello</h1>',
+    standalone: true,
+})
+], AppComponent);
+export { AppComponent };

crates/oxc_angular_compiler/tests/snapshots/integration_test__jit_full_component.snap

@@ -0,0 +1,26 @@
+---
+source: crates/oxc_angular_compiler/tests/integration_test.rs
+expression: result.code
+---
+import { Directive, Input, Output, HostBinding, EventEmitter } from '@angular/core';
+import { __decorate } from "tslib";
+
+let HighlightDirective = class HighlightDirective {
+    color: string = 'yellow';
+    title: string = '';
+    colorChange = new EventEmitter<string>();
+    isActive = false;
+
+static propDecorators = {
+    color: [{ type: Input }],
+    title: [{ type: Input, args: ['aliasName'] }],
+    colorChange: [{ type: Output }],
+    isActive: [{ type: HostBinding, args: ['class.active'] }]
+};
+};
+HighlightDirective = __decorate([
+    Directive({
+    selector: '[appHighlight]',
+})
+], HighlightDirective);
+export { HighlightDirective };

crates/oxc_angular_compiler/tests/snapshots/integration_test__jit_inline_template.snap

@@ -0,0 +1,17 @@
+---
+source: crates/oxc_angular_compiler/tests/integration_test.rs
+expression: result.code
+---
+import { Component } from '@angular/core';
+import { __decorate } from "tslib";
+import __NG_CLI_RESOURCE__0 from "angular:jit:style:file;./app.css";
+
+let AppComponent = class AppComponent {};
+AppComponent = __decorate([
+    Component({
+    selector: 'app-root',
+    template: '<h1>Hello</h1>',
+    styles: [__NG_CLI_RESOURCE__0],
+})
+], AppComponent);
+export { AppComponent };

crates/oxc_angular_compiler/tests/snapshots/integration_test__jit_prop_decorators.snap

@@ -0,0 +1,17 @@
+---
+source: crates/oxc_angular_compiler/tests/integration_test.rs
+expression: result.code
+---
+import { Component } from '@angular/core';
+import { __decorate } from "tslib";
+import __NG_CLI_RESOURCE__0 from "angular:jit:template:file;./app.html";
+
+let AppComponent = class AppComponent {};
+AppComponent = __decorate([
+    Component({
+    selector: 'app-root',
+    template: __NG_CLI_RESOURCE__0,
+    standalone: true,
+})
+], AppComponent);
+export { AppComponent };