Rewind chat or files from any user message (#1154)

* Add Pi extension-launch plumbing for in-process tree primitives

* Add Rewind controls for agent sessions

* Preserve SDK checkpoint env var so Claude file rewind works

The SDK injects CLAUDE_CODE_ENABLE_SDK_FILE_CHECKPOINTING=true when file checkpointing is enabled. The earlier parent-env stripping from c4782ec71c was too broad and removed that child flag along with real parent-session markers.

Keep stripping parent markers, but preserve the checkpoint flag so the SDK rewind path can run directly. With that boundary fixed, the JSONL file-rewind fallback is no longer needed.

* Update OpenCode history replay tests for rewind state

* Show Rewind actions in an adaptive sheet

* Fix rewind semantics across providers

* Refactor Pi IDs through extension capture

* Restore user message to composer after rewind

* Fix Claude rewind tool result mapping

* Fix Claude rewind session switch roundtrip

* Fix rewind and optimistic message regressions

* Tighten rewind test discipline

* Fix OpenCode optimistic message reconciliation

* Reconcile optimistic user messages by marker

* Reorder user message actions

* Unify provider user message contract

* Add Claude rewind flow Playwright contract

* Add Codex rewind flow Playwright contract

* Add OpenCode rewind flow Playwright contract

* Add Pi rewind flow Playwright contract

* Remove real-provider rewind Playwright contracts

* Gate real-provider rewind specs from CI Playwright

packages/app/src/agent-stream/view.tsx

@@ -412,16 +412,21 @@ const AgentStreamViewComponent = forwardRef<AgentStreamViewHandle, AgentStreamVi
       (layoutItem: StreamLayoutItem, item: Extract<StreamItem, { kind: "user_message" }>) => {
         return (
           <UserMessage
+            serverId={resolvedServerId}
+            agentId={agentId}
+            messageId={item.id}
             message={item.text}
             images={item.images}
             attachments={item.attachments}
             timestamp={item.timestamp.getTime()}
+            capabilities={agent.capabilities}
+            client={client}
             isFirstInGroup={layoutItem.isFirstInUserGroup}
             isLastInGroup={layoutItem.isLastInUserGroup}
           />
         );
       },
-      [],
+      [agent.capabilities, agentId, client, resolvedServerId],
     );
 
     const renderAssistantMessageItem = useCallback(