Spread AbsolutePathBuf (#17792)

Mechanical change to promote absolute paths through code.

codex-rs/core/src/codex_thread.rs

@@ -24,6 +24,7 @@ use codex_protocol::protocol::ThreadMemoryMode;
 use codex_protocol::protocol::TokenUsage;
 use codex_protocol::protocol::W3cTraceContext;
 use codex_protocol::user_input::UserInput;
+use codex_utils_absolute_path::AbsolutePathBuf;
 use rmcp::model::ReadResourceRequestParams;
 use std::collections::HashMap;
 use std::path::PathBuf;
@@ -40,7 +41,7 @@ pub struct ThreadConfigSnapshot {
     pub approval_policy: AskForApproval,
     pub approvals_reviewer: ApprovalsReviewer,
     pub sandbox_policy: SandboxPolicy,
-    pub cwd: PathBuf,
+    pub cwd: AbsolutePathBuf,
     pub ephemeral: bool,
     pub reasoning_effort: Option<ReasoningEffort>,
     pub personality: Option<Personality>,