qwen-local: the first provider that runs on our own GPU

sd-server (stable-diffusion.cpp, Vulkan) serving Qwen-Image 2.1 on this
machine. It already speaks OpenAI's image API, which is the vocabulary
`ImageRequest` is written in, so there is no translation layer — only the parts
that are true of a local GPU and not of a hosted one.

── keyless is a category, not an exception ──

`credentials.ts` decided a provider was usable by asking whether a key existed,
so a service that takes none read as unconfigured forever. The fix is an
adapter declaring `keyless`, not a dummy secret: a dummy would record a
credential that does not exist and make the secret store lie about what is
configured, and that store is the one place meant to be the truth about them.

A keyless adapter never reaches `keyFor` at all. That function's own comment
says why it uses `getSecret` rather than `getKey` — so a missing FOREIGN
credential is never minted — and a provider with no credential by design has no
business in that path.

whisper, OCR and TTS already run on this machine, so this will not be the last.

── measured, not assumed ──

The integration doc said "tens of seconds, not two". The server's own log says
512x512 completes in ~185s and 1024x1024 samples at ~41.4s/step over 20 steps,
about 14 minutes. And it serialises strictly: a second caller waits for the
first to finish entirely, so a queued 512 can wait 17 minutes before a byte
comes back.

So: 512 is the default and the substitute for `auto`, 1024 is offered with the
cost in its label, and `timeout: false` is a requirement rather than caution —
every default anyone would reach for is far under 17 minutes. The caller's
`signal` still aborts, because a user cancelling is not a client giving up.

── the model id moved, because only it could ──

`GET /v1/models` returns `sd-cpp-local`, hardcoded in sd-server with no
override. The catalogue now agrees with the server and carries "Qwen-Image 2.1
(local)" in the label, so requests name a model the server knows while the UI
still says something meaningful.

── not shipped: edit() ──

Same GPU, same queue. It doubles the ways generation can be blocked while the
generate path is unproven in anger, and `ImageAdapter` makes absence the way to
say so — the route answers 400 instead of the queue finding out late.

Verified: /v1/models answers, provider statuses report qwen-local as
configured/keyless/usable, and the shipped entry survives the merge with the
stored catalogue.json. NOT verified end to end — a generation is occupying the
GPU and I left it alone.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Officer-Session: de3ed4e6-f88a-429c-94e6-a760336ba83b

sidecar/providers/types.ts

@@ -85,6 +85,17 @@ export type ImageAdapter = {
   /** Models this adapter is known to serve. Advisory — an unknown model is passed through. */
   readonly models: readonly string[];
   readonly defaultModel: string;
+  /**
+   * This adapter authenticates with nothing, because it talks to a service of OURS rather than a
+   * vendor's. Availability is then a fact about the code, not about what is in the secret store.
+   *
+   * The alternative was storing a dummy secret so the existing "has a key?" test would pass. That would
+   * make the store lie about what is configured, and the store is the one place that is supposed to be
+   * the truth about credentials. A flag that says "this question does not apply" is smaller and honest.
+   *
+   * A category rather than an exception: whisper, OCR and TTS already run on this machine too.
+   */
+  readonly keyless?: boolean;
   /**
    * The key is passed in rather than read here: it can come from the database or the environment, and
    * which one is a question about configuration, not about how to talk to this provider.