fix(coding-agent): save initial model and thinking level to session

When creating a new session, initial model and thinking level were set
on the agent but never saved to session file. This caused --resume to
default thinking level to 'off'.

fixes #342

packages/coding-agent/CHANGELOG.md

@@ -198,6 +198,7 @@ Total color count increased from 46 to 50. See [docs/theme.md](docs/theme.md) fo
 
 ### Fixed
 
+- **Resuming session resets thinking level to off**: Initial model and thinking level were not saved to session file, causing `--resume`/`--continue` to default to `off`. ([#342](https://github.com/badlogic/pi-mono/issues/342))
 - **Edit tool fails on Windows due to CRLF line endings**: Files with CRLF line endings now match correctly when LLMs send LF-only text. Line endings are normalized before matching and restored to original style on write. ([#355](https://github.com/badlogic/pi-mono/issues/355) by [@Pratham-Dubey](https://github.com/Pratham-Dubey))
 - **Use bash instead of sh on Unix**: Fixed shell commands using `/bin/sh` instead of `/bin/bash` on Unix systems. ([#328](https://github.com/badlogic/pi-mono/pull/328) by [@dnouri](https://github.com/dnouri))
 - **OAuth login URL clickable**: Made OAuth login URLs clickable in terminal. ([#349](https://github.com/badlogic/pi-mono/pull/349) by [@Cursivez](https://github.com/Cursivez))

packages/coding-agent/src/core/sdk.ts

@@ -621,6 +621,12 @@ export async function createAgentSession(options: CreateAgentSessionOptions = {}
 	// Restore messages if session has existing data
 	if (hasExistingSession) {
 		agent.replaceMessages(existingSession.messages);
+	} else {
+		// Save initial model and thinking level for new sessions so they can be restored on resume
+		if (model) {
+			sessionManager.appendModelChange(model.provider, model.id);
+		}
+		sessionManager.appendThinkingLevelChange(thinkingLevel);
 	}
 
 	const session = new AgentSession({