Spread AbsolutePathBuf (#17792)

Mechanical change to promote absolute paths through code.

codex-rs/app-server-protocol/schema/json/v2/ThreadUnarchiveResponse.json

@@ -1,6 +1,10 @@
 {
   "$schema": "http://json-schema.org/draft-07/schema#",
   "definitions": {
+    "AbsolutePathBuf": {
+      "description": "A path that is guaranteed to be absolute and normalized (though it is not guaranteed to be canonicalized or exist on the filesystem).\n\nIMPORTANT: When deserializing an `AbsolutePathBuf`, a base path must be set using [AbsolutePathBufGuard::new]. If no base path is set, the deserialization will fail unless the path being deserialized is already absolute.",
+      "type": "string"
+    },
     "AgentPath": {
       "type": "string"
     },
@@ -217,7 +221,7 @@
               "type": "string"
             },
             "path": {
-              "type": "string"
+              "$ref": "#/definitions/AbsolutePathBuf"
             },
             "type": {
               "enum": [
@@ -794,8 +798,12 @@
           "type": "integer"
         },
         "cwd": {
-          "description": "Working directory captured for the thread.",
-          "type": "string"
+          "allOf": [
+            {
+              "$ref": "#/definitions/AbsolutePathBuf"
+            }
+          ],
+          "description": "Working directory captured for the thread."
         },
         "ephemeral": {
           "description": "Whether the thread is ephemeral and should not be materialized on disk.",
@@ -1080,8 +1088,12 @@
               "type": "array"
             },
             "cwd": {
-              "description": "The command's working directory.",
-              "type": "string"
+              "allOf": [
+                {
+                  "$ref": "#/definitions/AbsolutePathBuf"
+                }
+              ],
+              "description": "The command's working directory."
             },
             "durationMs": {
               "description": "The duration of the command execution in milliseconds.",
@@ -1410,7 +1422,7 @@
               "type": "string"
             },
             "path": {
-              "type": "string"
+              "$ref": "#/definitions/AbsolutePathBuf"
             },
             "type": {
               "enum": [
@@ -1443,9 +1455,13 @@
               ]
             },
             "savedPath": {
-              "type": [
-                "string",
-                "null"
+              "anyOf": [
+                {
+                  "$ref": "#/definitions/AbsolutePathBuf"
+                },
+                {
+                  "type": "null"
+                }
               ]
             },
             "status": {