Generate more typescript types and return conversation id with ConversationSummary (#3219)

This PR does multiple things that are necessary for conversation resume
to work from the extension. I wanted to make sure everything worked so
these changes wound up in one PR:
1. Generate more ts types
2. Resume rollout history files rather than create a new one every time
it is resumed so you don't see a duplicate conversation in history for
every resume. Chatted with @aibrahim-oai to verify this
3. Return conversation_id in conversation summaries
4. [Cleanup] Use serde and strong types for a lot of the rollout file
parsing

codex-rs/protocol/src/plan_tool.rs

@@ -1,8 +1,9 @@
 use serde::Deserialize;
 use serde::Serialize;
+use ts_rs::TS;
 
 // Types for the TODO tool arguments matching codex-vscode/todo-mcp/src/main.rs
-#[derive(Debug, Clone, Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize, TS)]
 #[serde(rename_all = "snake_case")]
 pub enum StepStatus {
     Pending,
@@ -10,14 +11,14 @@ pub enum StepStatus {
     Completed,
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize, TS)]
 #[serde(deny_unknown_fields)]
 pub struct PlanItemArg {
     pub step: String,
     pub status: StepStatus,
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize, TS)]
 #[serde(deny_unknown_fields)]
 pub struct UpdatePlanArgs {
     #[serde(default)]