Classify PromptKit generation errors safely

docs/integrations/pkg-promptkit.md

@@ -103,6 +103,10 @@ pinned upstream documentation.
 module assets, maps its transport-neutral completion contract, prepares and
 executes requests, validates output, records provenance, captures debug
 material, redacts errors, and preserves timeout ownership.
+
+PromptKit provider error details do not cross the ordinary completion boundary.
+Notarius exposes a provider-neutral generation category and optional status;
+redacted provider details are retained only in requested debug material.
 [D&D Module Internals](../internal/dnd.md) owns the embedded
 `dnd-extraction` fallback profile and the maintained D&D prompt defaults.
 [Configuration](../config.md#promptkit-profiles) defines how a Notarius

docs/internal/llm.md

@@ -256,6 +256,9 @@ redacted before it crosses the runtime boundary. Known-secret redaction is
 available to other runtime collaborators; it does not make prompt or response
 contents safe for general logging.
 
+Generation failures expose an application-owned category and optional HTTP
+status. Provider code, type, and message remain debug-only, after redaction.
+
 ## Failure Boundaries
 
 - Construction fails for missing asset registries, mutually exclusive profile

docs/roadmap/implementation.md

@@ -263,7 +263,7 @@ git diff --check
 - Current documentation accurately describes the implemented profile and
   credential behavior without duplicating PromptKit's merge algorithm.
 
-## Stage 4: Adapt Structured Generation Errors Safely
+## Stage 4: Adapt Structured Generation Errors Safely ✅
 
 ### Goal