chore(features) rm Feature::ApplyPatchFreeform (#22711)

## Summary
Removes the feature since this is effectively on by default in all cases
where we should use it, or can be configured via models.json.

## Testing
- [x] unit tests pass

codex-rs/features/src/legacy.rs

@@ -21,10 +21,6 @@ const ALIASES: &[Alias] = &[
         legacy_key: "experimental_use_unified_exec_tool",
         feature: Feature::UnifiedExec,
     },
-    Alias {
-        legacy_key: "include_apply_patch_tool",
-        feature: Feature::ApplyPatchFreeform,
-    },
     Alias {
         legacy_key: "request_permissions",
         feature: Feature::ExecPermissionApprovals,
@@ -67,18 +63,11 @@ pub(crate) fn feature_for_key(key: &str) -> Option<Feature> {
 
 #[derive(Debug, Default)]
 pub(crate) struct LegacyFeatureToggles {
-    pub include_apply_patch_tool: Option<bool>,
     pub experimental_use_unified_exec_tool: Option<bool>,
 }
 
 impl LegacyFeatureToggles {
     pub fn apply(self, features: &mut Features) {
-        set_if_some(
-            features,
-            Feature::ApplyPatchFreeform,
-            self.include_apply_patch_tool,
-            "include_apply_patch_tool",
-        );
         set_if_some(
             features,
             Feature::UnifiedExec,

codex-rs/features/src/lib.rs

@@ -99,7 +99,7 @@ pub enum Feature {
     ShellZshFork,
     /// Reflow transcript scrollback when the terminal is resized.
     TerminalResizeReflow,
-    /// Include the freeform apply_patch tool.
+    /// Removed compatibility flag for the deleted apply_patch fallback feature.
     ApplyPatchFreeform,
     /// Stream structured progress while apply_patch input is being generated.
     ApplyPatchStreamingEvents,
@@ -292,7 +292,6 @@ pub struct FeatureOverrides {
 #[derive(Debug, Clone, Copy, Default)]
 pub struct FeatureConfigSource<'a> {
     pub features: Option<&'a FeaturesToml>,
-    pub include_apply_patch_tool: Option<bool>,
     pub experimental_use_unified_exec_tool: Option<bool>,
 }
 
@@ -424,6 +423,9 @@ impl Features {
                 "remote_control" => {
                     continue;
                 }
+                "apply_patch_freeform" => {
+                    continue;
+                }
                 "image_detail_original" => {
                     continue;
                 }
@@ -465,7 +467,6 @@ impl Features {
 
         for source in [base, profile] {
             LegacyFeatureToggles {
-                include_apply_patch_tool: source.include_apply_patch_tool,
                 experimental_use_unified_exec_tool: source.experimental_use_unified_exec_tool,
             }
             .apply(&mut features);
@@ -822,8 +823,8 @@ pub const FEATURES: &[FeatureSpec] = &[
     FeatureSpec {
         id: Feature::ApplyPatchFreeform,
         key: "apply_patch_freeform",
-        stage: Stage::Stable,
-        default_enabled: true,
+        stage: Stage::Removed,
+        default_enabled: false,
     },
     FeatureSpec {
         id: Feature::ApplyPatchStreamingEvents,

codex-rs/features/src/tests.rs

@@ -66,6 +66,16 @@ fn image_detail_original_is_removed_and_disabled_by_default() {
     assert_eq!(Feature::ImageDetailOriginal.default_enabled(), false);
 }
 
+#[test]
+fn apply_patch_freeform_is_removed_and_disabled_by_default() {
+    assert_eq!(Feature::ApplyPatchFreeform.stage(), Stage::Removed);
+    assert_eq!(Feature::ApplyPatchFreeform.default_enabled(), false);
+    assert_eq!(
+        feature_for_key("apply_patch_freeform"),
+        Some(Feature::ApplyPatchFreeform)
+    );
+}
+
 #[test]
 fn code_mode_only_requires_code_mode() {
     let mut features = Features::with_defaults();
@@ -403,7 +413,6 @@ fn from_sources_applies_base_profile_and_overrides() {
         },
         FeatureConfigSource {
             features: Some(&profile_features),
-            include_apply_patch_tool: Some(true),
             ..Default::default()
         },
         FeatureOverrides {
@@ -414,7 +423,7 @@ fn from_sources_applies_base_profile_and_overrides() {
     assert_eq!(features.enabled(Feature::Plugins), true);
     assert_eq!(features.enabled(Feature::CodeModeOnly), true);
     assert_eq!(features.enabled(Feature::CodeMode), true);
-    assert_eq!(features.enabled(Feature::ApplyPatchFreeform), true);
+    assert_eq!(features.enabled(Feature::ApplyPatchFreeform), false);
     assert_eq!(features.enabled(Feature::WebSearchRequest), false);
 }
 
@@ -472,6 +481,23 @@ fn from_sources_ignores_removed_js_repl_feature_keys() {
     assert_eq!(features, Features::with_defaults());
 }
 
+#[test]
+fn from_sources_ignores_removed_apply_patch_freeform_feature_key() {
+    let features_toml =
+        FeaturesToml::from(BTreeMap::from([("apply_patch_freeform".to_string(), true)]));
+
+    let features = Features::from_sources(
+        FeatureConfigSource {
+            features: Some(&features_toml),
+            ..Default::default()
+        },
+        FeatureConfigSource::default(),
+        FeatureOverrides::default(),
+    );
+
+    assert_eq!(features, Features::with_defaults());
+}
+
 #[test]
 fn multi_agent_v2_feature_config_deserializes_boolean_toggle() {
     let features: FeaturesToml = toml::from_str(
@@ -587,14 +613,13 @@ fn materialize_resolved_enabled_writes_all_features_and_preserves_custom_config(
             proxy_url: Some("http://127.0.0.1:43128".to_string()),
             ..Default::default()
         })),
-        entries: BTreeMap::from([("include_apply_patch_tool".to_string(), true)]),
+        entries: BTreeMap::new(),
         ..Default::default()
     };
 
     features_toml.materialize_resolved_enabled(&features);
 
     let entries = features_toml.entries();
-    assert_eq!(entries.get("include_apply_patch_tool"), None);
     for spec in crate::FEATURES {
         assert_eq!(
             entries.get(spec.key),
@@ -627,7 +652,7 @@ fn materialize_resolved_enabled_writes_all_features_and_preserves_custom_config(
         FeatureConfigSource::default(),
         FeatureOverrides::default(),
     );
-    assert_eq!(replayed.enabled(Feature::ApplyPatchFreeform), true);
+    assert_eq!(replayed.enabled(Feature::ApplyPatchFreeform), false);
 }
 
 #[test]