fix(coding-agent): parse quoted import paths and missing files

packages/coding-agent/src/core/agent-session-runtime.ts

@@ -33,6 +33,16 @@ export type CreateAgentSessionRuntimeFactory = (options: {
 	sessionStartEvent?: SessionStartEvent;
 }) => Promise<CreateAgentSessionRuntimeResult>;
 
+export class SessionImportFileNotFoundError extends Error {
+	readonly filePath: string;
+
+	constructor(filePath: string) {
+		super(`File not found: ${filePath}`);
+		this.name = "SessionImportFileNotFoundError";
+		this.filePath = filePath;
+	}
+}
+
 function extractUserMessageText(content: string | Array<{ type: string; text?: string }>): string {
 	if (typeof content === "string") {
 		return content;
@@ -251,7 +261,7 @@ export class AgentSessionRuntime {
 	async importFromJsonl(inputPath: string, cwdOverride?: string): Promise<{ cancelled: boolean }> {
 		const resolvedPath = resolve(inputPath);
 		if (!existsSync(resolvedPath)) {
-			throw new Error(`File not found: ${resolvedPath}`);
+			throw new SessionImportFileNotFoundError(resolvedPath);
 		}
 
 		const sessionDir = this.session.sessionManager.getSessionDir();