feat(angular): derive .observable() options from the installed HttpClient

[pkurcx]

Summary

ObservableOptions in templates/angular/rest.model.ts was a hand-kept list, so it fell behind Angular. On Angular 22 .observable() rejected integrity, referrer, referrerPolicy, reportUploadProgress and reportDownloadProgress, and reportProgress lost its @deprecated marker.

It is now derived from the consumer's own HttpClient:

export type ObservableOptions = Omit<
  NonNullable<Parameters<HttpClient['request']>[2]>,
  'body' | 'params' | 'headers' | 'responseType'
> & { injector?: Injector };

Parameters reads request()'s last overload, its catch-all. Options a later Angular adds therefore pass through without a release or a regeneration. The runtime already spread every option into HttpClient.request, so only the type changes.

• Proof (service-proof.ts): compares the option keys against HttpClient's, because a non-literal argument skips excess-property checks. It also calls .observable() with the five new options, and keeps @ts-expect-error checks for the four keys the operation supplies. Before the fix, the key check failed and named exactly the five missing options.
• Docs and README: the options paragraph now says the options come from the installed Angular. Examples use reportUploadProgress / reportDownloadProgress instead of the deprecated reportProgress.

Test plan

• bun run test: 400 passed
• cargo test: 325 passed
• bun run typecheck, bun run lint
• bun run regen-snapshots: only static-template/rest.model.ts changed
• Generated client plus the key and option checks compile on Angular 20.3 (TS 5.8) and 21.2 (TS 5.9), checked by hand since the suite gates 22
• Editor completions mark reportProgress deprecated on .observable(), the same as on HttpClient.request

After release: regenerate stackblitz/src/generated, which still carries the hand-kept list from 0.7.0.

🤖 Generated with Claude Code