Add Promptkit-owned profile definitions

docs/formats.md

@@ -283,7 +283,8 @@ Profile sources resolve matching IDs in this order:
 2. the ordinary configured source selected by a profile file, `fs.FS`, or
    configured profile directory;
 3. application fallback profiles supplied with `WithFallbackProfileFS`; and
-4. maintained external catalog profiles.
+4. Promptkit-owned profiles; and
+5. maintained external catalog profiles.
 
 A profile source supplies a complete definition; definitions and their fields
 are not merged across sources. A higher-precedence source falls back only when
@@ -326,6 +327,18 @@ that backend's connection and credential metadata. Profile files do not repeat
 those values. A configured, application fallback, or in-memory profile with
 the same profile ID takes precedence.
 
+Promptkit owns two opt-in profiles. Their following definitions are current
+selections, not automatic defaults:
+
+| ID | Current definition |
+| --- | --- |
+| `promptkit-openrouter-standard` | Inherits `gemini-flash-latest`. |
+| `promptkit-openrouter-auto` | Selects backend `openrouter` and model `openrouter/auto`. |
+
+Select either name through an existing request `profile_id` or prompt
+`default_profile`. Consumers can replace either definition or its inherited
+base through the ordinary profile-source precedence above.
+
 | Provider | ID | Backend | Model |
 | --- | --- | --- | --- |
 | aion-labs | `aion-2` | `openrouter` | `aion-labs/aion-2.0` |