fix(jit): elide imports whose specifiers are all inline-type

[ashley-hunter]

Problem

With jit: true, an import statement whose bindings all carry inline type modifiers is preserved as a bare side-effect import instead of being elided:

import { Pipe, type PipeTransform } from '@angular/core';
import { type Get } from 'type-fest';

@Pipe({ name: 'demo' })
export class DemoPipe implements PipeTransform {
  transform(v: string) { return v; }
}

export let sample: Get<{ a: 1 }, 'a'> | undefined;

emits import "type-fest"; at the top of the output. For a types-only package like type-fest (no main/exports), Rolldown fails the build outright; for an ordinary package it survives as a dead import that defeats tree-shaking.

The file must contain an Angular decorator to reproduce, which points at the JIT transform: strip_typescript runs oxc's TS transform with only_remove_type_imports, which drops the inline-type specifiers but keeps the emptied statement as a side-effect import. Mixed imports (import { Pipe, type PipeTransform }) and whole import type { ... } statements were already handled correctly; only the all-inline-type case leaked.

Fix

Before the transformer runs, promote any value import whose named specifiers are all inline-type to import type, so only_remove_type_imports elides the whole statement. Untouched: bare side-effect imports (import 'mod'), empty import {}, existing import type, and any statement with a default or namespace specifier.

Note this intentionally follows Angular CLI's esbuild pipeline rather than tsc verbatimModuleSyntax, which would keep import {} for side effects; code relying on side effects should use an explicit import 'mod', which is preserved.

AOT is unaffected: it uses the separate semantic-based elision pass and already elides these imports.

Testing

• New integration test covering all five import shapes: all-inline-type elided, mixed value+type keeps the value binding only, whole import type elided, default import with inline-type sibling keeps the default, bare side-effect import preserved. Fails before the fix with the exact reported output, passes after.
• Full workspace test suite passes (2763 tests), fmt and clippy clean.
• Verified end-to-end through the napi binding with jit: true and jit: false on the repro above.