Attribute executor skill invocations to plugins (#39309)

## What changed

- Carry selected plugin identities from MCP discovery into per-turn extension data, limited to capability roots that are ready for the turn.
- Annotate executor skill catalog entries with the matching plugin ID and `user` scope.
- Include that attribution in `skill_invocation` analytics for both explicit and implicit executor skill invocations.

## Testing

- Extend the executor skills app-server test to verify plugin ID, skill scope, and invocation type for explicit and implicit analytics events.

GitOrigin-RevId: 9345600ae29bcb8eb894fffd2d6f7b05f22ebf74

codex-rs/ext/extension-api/src/contributors.rs

@@ -25,6 +25,8 @@ mod world_state;
 pub use context::TurnContextContributionInput;
 pub use mcp::McpServerContribution;
 pub use mcp::McpServerContributionContext;
+pub use mcp::SelectedPluginIdentity;
+pub use mcp::SelectedPluginSnapshot;
 pub use prompt::PromptFragment;
 pub use prompt::PromptSlot;
 pub use skill_invocation::SkillInvocationInput;

codex-rs/ext/extension-api/src/contributors/mcp.rs

@@ -112,6 +112,19 @@ impl<'a, C> McpServerContributionContext<'a, C> {
     }
 }
 
+/// Validated plugin identities projected for the current set of selected roots.
+#[derive(Clone, Debug, Default)]
+pub struct SelectedPluginSnapshot {
+    pub plugins: Vec<SelectedPluginIdentity>,
+}
+
+/// The configured identity of a plugin resolved from one selected root.
+#[derive(Clone, Debug)]
+pub struct SelectedPluginIdentity {
+    pub selected_root_id: String,
+    pub plugin_id: String,
+}
+
 /// One extension-owned overlay for the runtime MCP server configuration.
 #[derive(Clone, Debug)]
 pub enum McpServerContribution {
@@ -130,6 +143,7 @@ pub enum McpServerContribution {
     },
     /// Records a plugin selected for this thread and any connector IDs it declares.
     SelectedPluginPackage {
+        selected_root_id: String,
         plugin_id: String,
         plugin_display_name: String,
         connector_ids: Vec<String>,

codex-rs/ext/extension-api/src/lib.rs

@@ -46,6 +46,8 @@ pub use contributors::PreviousWorldStateSection;
 pub use contributors::PromptFragment;
 pub use contributors::PromptSlot;
 pub use contributors::RenderedWorldStateFragment;
+pub use contributors::SelectedPluginIdentity;
+pub use contributors::SelectedPluginSnapshot;
 pub use contributors::SkillInvocationContributor;
 pub use contributors::SkillInvocationInput;
 pub use contributors::SkillInvocationKind;