chore: Nest skill and protocol network permissions under network.enabled (#13427)

## Summary

Changes the permission profile shape from a bare network boolean to a
nested object.

Before:

```yaml
permissions:
  network: true
```

After:

```yaml
permissions:
  network:
    enabled: true
```

This also updates the shared Rust and app-server protocol types so
`PermissionProfile.network` is no longer `Option<bool>`, but
`Option<NetworkPermissions>` with `enabled: Option<bool>`.

## What Changed

- Updated `PermissionProfile` in `codex-rs/protocol/src/models.rs`:
- `pub network: Option<bool>` -> `pub network:
Option<NetworkPermissions>`
- Added `NetworkPermissions` with:
  - `pub enabled: Option<bool>`
- Changed emptiness semantics so `network` is only considered empty when
`enabled` is `None`
- Updated skill metadata parsing to accept `permissions.network.enabled`
- Updated core permission consumers to read
`network.enabled.unwrap_or(false)` where a concrete boolean is needed
- Updated app-server v2 protocol types and regenerated schema/TypeScript
outputs
- Updated docs to mention `additionalPermissions.network.enabled`

codex-rs/core/src/sandboxing/mod.rs

@@ -193,7 +193,12 @@ fn merge_network_access(
     base_network_access: bool,
     additional_permissions: &PermissionProfile,
 ) -> bool {
-    base_network_access || matches!(additional_permissions.network, Some(true))
+    base_network_access
+        || additional_permissions
+            .network
+            .as_ref()
+            .and_then(|network| network.enabled)
+            .unwrap_or(false)
 }
 
 fn sandbox_policy_with_additional_permissions(
@@ -431,6 +436,7 @@ mod tests {
     use crate::tools::sandboxing::SandboxablePreference;
     use codex_protocol::config_types::WindowsSandboxLevel;
     use codex_protocol::models::FileSystemPermissions;
+    use codex_protocol::models::NetworkPermissions;
     use codex_protocol::models::PermissionProfile;
     use codex_utils_absolute_path::AbsolutePathBuf;
     use dunce::canonicalize;
@@ -470,7 +476,9 @@ mod tests {
         )
         .expect("absolute temp dir");
         let permissions = normalize_additional_permissions(PermissionProfile {
-            network: Some(true),
+            network: Some(NetworkPermissions {
+                enabled: Some(true),
+            }),
             file_system: Some(FileSystemPermissions {
                 read: Some(vec![path.clone()]),
                 write: Some(vec![path.clone()]),
@@ -479,7 +487,12 @@ mod tests {
         })
         .expect("permissions");
 
-        assert_eq!(permissions.network, Some(true));
+        assert_eq!(
+            permissions.network,
+            Some(NetworkPermissions {
+                enabled: Some(true),
+            })
+        );
         assert_eq!(
             permissions.file_system,
             Some(FileSystemPermissions {
@@ -505,7 +518,9 @@ mod tests {
                 network_access: false,
             },
             &PermissionProfile {
-                network: Some(true),
+                network: Some(NetworkPermissions {
+                    enabled: Some(true),
+                }),
                 file_system: Some(FileSystemPermissions {
                     read: Some(vec![path.clone()]),
                     write: Some(Vec::new()),

codex-rs/core/src/skills/loader.rs

@@ -32,6 +32,8 @@ use tracing::error;
 
 #[cfg(test)]
 use crate::config::Config;
+#[cfg(test)]
+use codex_protocol::models::NetworkPermissions;
 
 #[derive(Debug, Deserialize)]
 struct SkillFrontmatter {
@@ -1387,7 +1389,8 @@ policy: {}
             skill_dir,
             r#"
 permissions:
-  network: true
+  network:
+    enabled: true
   file_system:
     read:
       - "./data"
@@ -1408,7 +1411,9 @@ permissions:
         assert_eq!(
             outcome.skills[0].permission_profile,
             Some(PermissionProfile {
-                network: Some(true),
+                network: Some(NetworkPermissions {
+                    enabled: Some(true),
+                }),
                 file_system: Some(FileSystemPermissions {
                     read: Some(vec![
                         AbsolutePathBuf::try_from(normalized(skill_dir.join("data").as_path()))

codex-rs/core/src/skills/permissions.rs

@@ -44,7 +44,7 @@ pub(crate) fn compile_permission_profile(
         file_system,
         macos,
     } = permissions?;
-    let network_access = network.unwrap_or_default();
+    let network_access = network.and_then(|value| value.enabled).unwrap_or_default();
     let file_system = file_system.unwrap_or_default();
     let fs_read = normalize_permission_paths(
         file_system.read.as_deref().unwrap_or_default(),
@@ -232,6 +232,7 @@ mod tests {
     use codex_protocol::models::MacOsPermissions;
     #[cfg(target_os = "macos")]
     use codex_protocol::models::MacOsPreferencesValue;
+    use codex_protocol::models::NetworkPermissions;
     use codex_protocol::models::PermissionProfile;
     use codex_utils_absolute_path::AbsolutePathBuf;
     use pretty_assertions::assert_eq;
@@ -251,7 +252,9 @@ mod tests {
         fs::create_dir_all(&read_dir).expect("read dir");
 
         let profile = compile_permission_profile(Some(PermissionProfile {
-            network: Some(true),
+            network: Some(NetworkPermissions {
+                enabled: Some(true),
+            }),
             file_system: Some(FileSystemPermissions {
                 read: Some(vec![
                     absolute_path(&skill_dir.join("data")),
@@ -318,7 +321,9 @@ mod tests {
         fs::create_dir_all(&skill_dir).expect("skill dir");
 
         let profile = compile_permission_profile(Some(PermissionProfile {
-            network: Some(true),
+            network: Some(NetworkPermissions {
+                enabled: Some(true),
+            }),
             ..Default::default()
         }))
         .expect("profile");
@@ -353,7 +358,9 @@ mod tests {
         fs::create_dir_all(&read_dir).expect("read dir");
 
         let profile = compile_permission_profile(Some(PermissionProfile {
-            network: Some(true),
+            network: Some(NetworkPermissions {
+                enabled: Some(true),
+            }),
             file_system: Some(FileSystemPermissions {
                 read: Some(vec![absolute_path(&skill_dir.join("data"))]),
                 write: Some(Vec::new()),