Remove generated-default filesystem path variants (#33632)

## What changed

- Represent built-in filesystem policy entries with the same `Path` and
  `Special` variants used by other entries.
- Remove generated-default filtering from Windows sandbox policy resolution and
  simplify elevated deny-write handling to rely on direct-runtime enforcement
  and the legacy policy projection.
- Update protocol conversions, policy transforms, and profile expectations for
  the reduced filesystem path model.

GitOrigin-RevId: a65793e6855a03d52a575e82cb3d4b9b2e32db5c

codex-rs/file-system/src/lib.rs

@@ -126,10 +126,8 @@ pub struct WalkOutcome {
 #[serde(tag = "type", rename_all = "snake_case")]
 pub enum ExecFileSystemPath {
     Path { path: PathUri },
-    GeneratedDefaultPath { path: PathUri },
     GlobPattern { pattern: String },
     Special { value: FileSystemSpecialPath },
-    GeneratedDefaultSpecial { value: FileSystemSpecialPath },
 }
 
 impl From<FileSystemPath> for ExecFileSystemPath {
@@ -138,14 +136,8 @@ impl From<FileSystemPath> for ExecFileSystemPath {
             FileSystemPath::Path { path } => Self::Path {
                 path: PathUri::from_abs_path(&path),
             },
-            FileSystemPath::GeneratedDefaultPath { path } => Self::GeneratedDefaultPath {
-                path: PathUri::from_abs_path(&path),
-            },
             FileSystemPath::GlobPattern { pattern } => Self::GlobPattern { pattern },
             FileSystemPath::Special { value } => Self::Special { value },
-            FileSystemPath::GeneratedDefaultSpecial { value } => {
-                Self::GeneratedDefaultSpecial { value }
-            }
         }
     }
 }
@@ -158,14 +150,8 @@ impl TryFrom<ExecFileSystemPath> for FileSystemPath {
             ExecFileSystemPath::Path { path } => Self::Path {
                 path: path.to_abs_path()?,
             },
-            ExecFileSystemPath::GeneratedDefaultPath { path } => Self::GeneratedDefaultPath {
-                path: path.to_abs_path()?,
-            },
             ExecFileSystemPath::GlobPattern { pattern } => Self::GlobPattern { pattern },
             ExecFileSystemPath::Special { value } => Self::Special { value },
-            ExecFileSystemPath::GeneratedDefaultSpecial { value } => {
-                Self::GeneratedDefaultSpecial { value }
-            }
         })
     }
 }
@@ -364,14 +350,8 @@ impl FileSystemSandboxContext {
                 ExecFileSystemPath::GlobPattern { pattern } => !Path::new(pattern).is_absolute(),
                 ExecFileSystemPath::Special {
                     value: FileSystemSpecialPath::ProjectRoots { .. },
-                }
-                | ExecFileSystemPath::GeneratedDefaultSpecial {
-                    value: FileSystemSpecialPath::ProjectRoots { .. },
                 } => true,
-                ExecFileSystemPath::Path { .. }
-                | ExecFileSystemPath::GeneratedDefaultPath { .. }
-                | ExecFileSystemPath::Special { .. }
-                | ExecFileSystemPath::GeneratedDefaultSpecial { .. } => false,
+                ExecFileSystemPath::Path { .. } | ExecFileSystemPath::Special { .. } => false,
             }),
             ExecPermissionProfile::Managed {
                 file_system: ExecManagedFileSystemPermissions::Unrestricted,