Restore agent tool panes and require explicit session resume

Persist direct-provider tool calls, results, display details, and turn identities so saved conversations rebuild individual panes. Keep restored runs dormant until explicitly resumed and bind queued shell commands to their actual execution blocks.

app/src/ai/agent/api/convert_from.rs

@@ -215,6 +215,8 @@ fn convert_start_agent_v2_execution_mode(
 /// Unexpected errors when trying to convert an [`api::Message`] to an [`AIAgentOutputMessage`].
 #[derive(Debug, thiserror::Error)]
 pub enum MessageToAIAgentOutputMessageError {
+    #[error("Invalid saved provider tool: {0}")]
+    SavedProviderTool(String),
     #[error("Missing expected message")]
     MissingMessage,
     #[error("Error converting tool to action: {0:?}")]
@@ -262,6 +264,16 @@ impl ConvertAPIMessageToClientOutputMessage for api::Message {
         self,
         params: ConversionParams,
     ) -> Result<MaybeAIAgentOutputMessage, MessageToAIAgentOutputMessageError> {
+        if let Some(action) =
+            crate::ai::agent::provider_history::restore_tool(&self.server_message_data)
+        {
+            return Ok(MaybeAIAgentOutputMessage::Message(
+                AIAgentOutputMessage::action(
+                    MessageId::new(self.id),
+                    action.map_err(MessageToAIAgentOutputMessageError::SavedProviderTool)?,
+                ),
+            ));
+        }
         let Some(message) = self.message else {
             // In shared-session streams we can receive skeleton placeholder task messages without payloads.
             // Treat them as having no client representation rather than erroring and aborting ingestion entirely.