feat: feature-gate local inference dependencies (#7976)

Signed-off-by: DaeHee Lee <lee111dae11@proton.me>
Signed-off-by: jh-block <jhugo@block.xyz>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Co-authored-by: jh-block <jhugo@block.xyz>

ui/desktop/openapi.json

@@ -1922,6 +1922,26 @@
         }
       }
     },
+    "/features": {
+      "get": {
+        "tags": [
+          "super::routes::features"
+        ],
+        "operationId": "get_features",
+        "responses": {
+          "200": {
+            "description": "Compile-time feature flags",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/FeaturesResponse"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
     "/handle_nanogpt": {
       "post": {
         "tags": [
@@ -5333,6 +5353,21 @@
           }
         }
       },
+      "FeaturesResponse": {
+        "type": "object",
+        "required": [
+          "features"
+        ],
+        "properties": {
+          "features": {
+            "type": "object",
+            "description": "Map of feature name to enabled status",
+            "additionalProperties": {
+              "type": "boolean"
+            }
+          }
+        }
+      },
       "ForkRequest": {
         "type": "object",
         "required": [