[skills] Auto install MCP dependencies when running skils with dependency specs. (#9982)

Auto install MCP dependencies when running skils with dependency specs.

codex-rs/core/src/features.rs

@@ -109,6 +109,8 @@ pub enum Feature {
     Collab,
     /// Enable connectors (apps).
     Connectors,
+    /// Allow prompting and installing missing MCP dependencies.
+    SkillMcpDependencyInstall,
     /// Steer feature flag - when enabled, Enter submits immediately instead of queuing.
     Steer,
     /// Enable collaboration modes (Plan, Code, Pair Programming, Execute).
@@ -449,6 +451,12 @@ pub const FEATURES: &[FeatureSpec] = &[
         stage: Stage::UnderDevelopment,
         default_enabled: false,
     },
+    FeatureSpec {
+        id: Feature::SkillMcpDependencyInstall,
+        key: "skill_mcp_dependency_install",
+        stage: Stage::Stable,
+        default_enabled: true,
+    },
     FeatureSpec {
         id: Feature::Steer,
         key: "steer",