Forward sessions through PromptKit requests

docs/internal/llm.md

@@ -26,12 +26,15 @@ durable schemas. Those responsibilities remain with the module and its
 
 `PromptKitClient` validates the request target and prompt identity, maps each
 named material to a PromptKit inline artifact while preserving its origin URI,
-maps the request session to the existing `session_id` prompt variable, forwards
-profile selection, then prepares and runs the prompt. PromptKit v0.1.0 has no
-direct request-level session field. The adapter returns PromptKit’s validated
-raw bytes rather than re-encoding the decoded target. An empty optional
-material is represented as one space so its named input is retained by
-PromptKit.
+maps the trimmed request session to PromptKit's direct per-run session field,
+retains the same value as the `session_id` prompt variable for maintained
+prompt compatibility, forwards profile selection, then prepares and runs the
+prompt. The direct field is authoritative for provider session behavior. A
+session ID is a stable, non-secret correlation identifier and may be exposed
+to providers and provider observability. The adapter returns PromptKit’s
+validated raw bytes rather than re-encoding the decoded target. An empty
+optional material is represented as one space so its named input is retained
+by PromptKit.
 
 An empty request profile lets the prompt select its configured default. The CLI
 prepares every explicitly selected binding profile before a run begins, so a
@@ -136,7 +139,7 @@ does not install another timeout wrapper around PromptKit.
 
 The selected PromptKit profile owns generation settings. Notarius binding
 retries remain outside the adapter and repeat the complete module operation
-and validation chain. PromptKit v0.1.0 does not add a provider retry loop.
+and validation chain. PromptKit does not add a provider retry loop.
 Operator-facing behavior is summarized in
 [Operations](../operations.md#operational-limits), and the pinned upstream
 contract is identified in