Remove bundled catalog integration

docs/consumers/pkg-promptkit.md

@@ -109,8 +109,8 @@ input := configkit.Input{Source: document}
 ```
 
 `ProfileSource` and `BackendSource` are smaller typed conveniences when null
-is not needed. A caller underlay can overlay catalog backend fields just as it
-can overlay profiles; there is no registration-only backend namespace.
+is not needed. Backend and profile definitions are supplied by the caller;
+there is no registration-only backend namespace.
 
 When configuration or message files change, build and validate a new engine,
 then switch the application to that engine for subsequent work. Existing
@@ -614,75 +614,14 @@ rules; the maintained examples show complete runnable workflows.
 
 ### Choose A Profile Ownership Model
 
-Choose the profile source that matches the application's continuity needs:
-
-- Select `promptkit-openrouter-standard` or `promptkit-openrouter-auto` when
-  the maintained literal name is the desired consumer contract. Their current
-  selections are in the [format reference](../formats.md#built-in-profile-catalog).
-- Select an external catalog profile directly when the application accepts that
-  profile's catalog volatility. The selected external inventories are linked
-  from the [format reference](../formats.md#external-profile-inventories).
-- Define a complete application-owned profile with an explicit backend or
-  endpoint, model, and settings when the application owns those choices.
-
-An application profile that inherits an external base follows later changes to
-that base and fails if the base disappears; it is not a frozen copy. Promptkit
-tests the catalog versions selected in its module graph. Independently advancing
-a catalog dependency can remove an inherited base and produce an untested
-combination. Pinning the resolved module graph preserves the embedded data for
-a build, but cannot preserve provider availability. Running binaries neither
-download catalog updates nor automatically replace withdrawn models. See the
-[release policy](../policy/release.md#catalog-profile-compatibility) for the exact
-cross-version guarantees.
-
-### Alias A Built-In Profile
-
-Give an application-owned profile ID a built-in base when prompts should select
-the application ID while inheriting the built-in target. The child can override
-only the setting it owns:
-
-```go
-profile := promptkit.ProfileSource("application profiles", map[string]promptkit.ProfileConfig{
-	"weather-light": {
-		Extends: &standardID,
-		ReasoningEffort: &high,
-	},
-})
-```
-
-Place `profile` in a ConfigKit underlay, with `standardID` set to
-`"promptkit-openrouter-standard"` and `high` to `"high"`. Select
-`weather-light` in a prompt or `RunRequest.ProfileID`; it remains the
-reported selected profile. Definition IDs and inheritance references are exact
-keys. If the base is an external profile, apply the volatility guidance
-above when deciding whether to use an application-owned complete definition
-instead.
-
-### Use The Rakestrawhome Built-In Profile
-
-Set `RAKESTRAWHOME_INFERENCE_API_KEY` in the application environment, then
-select `rakestrawhome-gemma-4-31b` as an ordinary profile ID. For example, a
-prepared result identifies the selected built-in through
-`BackendRakestrawHome`:
-
-```go
-prepared, err := engine.Prepare(ctx, promptkit.RunRequest{
-	PromptID:  "meeting.summary",
-	ProfileID: "rakestrawhome-gemma-4-31b",
-	Inputs:    inputs,
-})
-if err != nil {
-	return err
-}
-if prepared.SelectedBackendID != promptkit.BackendRakestrawHome {
-	return fmt.Errorf("unexpected backend %q", prepared.SelectedBackendID)
-}
-```
-
-The maintained catalog supplies this backend, and callers may overlay its
-effective configuration through a later ConfigKit source. Direct request credentials
-and runtime endpoint overrides remain supported under their ordinary GoDoc and
-format contracts.
+Supply backend and profile definitions through the configuration sources your
+application selects. PromptKit does not install provider catalogs or built-in
+profile inventories; conventional backend ID constants are names only. Define
+the model, endpoint, credentials lookup, and settings that your application
+intends to support. Profiles may inherit another configured profile using an
+exact ID, and caller-selected source layers determine the final values. The
+[format reference](../formats.md) describes the definition fields and
+composition rules.
 
 ### Inspect A Profile Before Prompt Work