Use turn environment permissions for context and discovery (#37040)

## What changed

- Build filesystem and permission context from the primary turn environment's permission profile, working directory, and workspace roots, falling back to the thread context when no primary environment is available.
- Build capability-discovery sandbox contexts from each environment's permission profile and treat discovery as restricted when any selected environment has restricted filesystem access.

## Testing

- Add regression tests covering environment-specific capability discovery and permission context updates.

GitOrigin-RevId: 6bbbd9b88aafa5e6583971ce4e427fc7557f2d93

codex-rs/core/src/context/world_state/environment.rs

@@ -6,7 +6,6 @@ use crate::context::environment_context::NetworkContext;
 use crate::context::environment_context::push_xml_escaped_text;
 use crate::environment_selection::TurnEnvironmentSnapshot;
 use crate::session::turn_context::TurnContext;
-use crate::session::turn_context::TurnEnvironment;
 use codex_utils_path_uri::PathUri;
 use serde::Deserialize;
 use serde::Serialize;
@@ -29,19 +28,17 @@ impl EnvironmentsState {
         environments: &TurnEnvironmentSnapshot,
         current_date: Option<String>,
     ) -> Self {
-        let workspace_roots = environments
-            .primary()
-            .map(TurnEnvironment::workspace_roots)
-            .unwrap_or_default();
         Self {
             environments: environment_states(environments),
             current_date,
             timezone: turn_context.timezone.clone(),
             network: network_from_turn_context(turn_context),
-            filesystem: Some(FileSystemContext::from_permission_profile(
-                turn_context.config.permissions.permission_profile(),
-                workspace_roots,
-            )),
+            filesystem: environments.primary().map(|environment| {
+                FileSystemContext::from_permission_profile(
+                    environment.permission_profile(),
+                    environment.workspace_roots(),
+                )
+            }),
             subagents: None,
         }
     }