Merge pinned master into status bar projection

docs/core-data-structures/session.md

@@ -154,7 +154,7 @@ interface TodoItem {
 
 ### The request header event: `request/header`
 
-The request envelope — the `EpochHeader` (call config + rendered system prompt + assembled tool schemas) — is logged session state, so every conversation request is a pure function of the log (the reconstructability Agent Note). A full `request/header` snapshot with reason `'initial'` or `'resume'` records each loop-instance boundary; a later changed request records another full snapshot with reason `'change'`. `foldRequestHeader(events)` reconstructs the header by selecting the latest snapshot. The event is not a `SurfaceEventType`: it produces no LLM message.
+The request envelope — the `EpochHeader` (call config + adapter-default provenance + rendered system prompt + assembled tool schemas) — is logged session state, so every conversation request is a pure function of the log (the reconstructability Agent Note). A full `request/header` snapshot with reason `'initial'` or `'resume'` records each loop-instance boundary; a later changed request records another full snapshot with reason `'change'`. `foldRequestHeader(events)` reconstructs the header by selecting the latest snapshot. The event is not a `SurfaceEventType`: it produces no LLM message.
 
 ```ts type-equiv
 /**
@@ -165,6 +165,8 @@ The request envelope — the `EpochHeader` (call config + rendered system prompt
 interface EpochHeader {
   /** The conversation's call configuration (provider, model, reasoning effort, and sampling scalars). */
   config: LlmCallConfig
+  /** Effective config fields materialized from the exact adapter rather than proposed by a caller. */
+  adapterDefaults?: LlmCallConfigAdapterDefaults
   /** Rendered system prompt text; absent for a system-less request. */
   system?: string
   /** Assembled tool schemas; absent for a tool-less request. */