docs: add google_auth configuration section and update schema

- Add Google Auth subsection to Configuration in README.md/README.ko.md
- Add google_auth and lsp options to oh-my-opencode.schema.json

🤖 GENERATED WITH ASSISTANCE OF [OhMyOpenCode](https://github.com/code-yeongyu/oh-my-opencode)

Author: code-yeongyu

README.ko.md

@@ -441,6 +441,18 @@ Schema 자동 완성이 지원됩니다:
 }
 ```
 
+### Google Auth
+
+Google Gemini 모델을 위한 내장 Antigravity OAuth를 활성화합니다:
+
+```json
+{
+  "google_auth": true
+}
+```
+
+활성화하면 `opencode auth login` 실행 시 Google 프로바이더에서 "OAuth with Google (Antigravity)" 로그인 옵션이 표시됩니다.
+
 ### Agents
 
 내장 에이전트 설정을 오버라이드할 수 있습니다:

README.md

@@ -439,6 +439,18 @@ Schema autocomplete is supported:
 }
 ```
 
+### Google Auth
+
+Enable built-in Antigravity OAuth for Google Gemini models:
+
+```json
+{
+  "google_auth": true
+}
+```
+
+When enabled, `opencode auth login` will show "OAuth with Google (Antigravity)" as a login option for the Google provider.
+
 ### Agents
 
 Override built-in agent settings:

assets/oh-my-opencode.schema.json

@@ -155,6 +155,47 @@
         }
       }
     },
+    "google_auth": {
+      "type": "boolean",
+      "description": "Enable built-in Antigravity OAuth for Google Gemini models. When true, adds 'OAuth with Google (Antigravity)' login option.",
+      "default": false
+    },
+    "lsp": {
+      "type": "object",
+      "description": "Additional LSP server configurations specific to Oh My OpenCode.",
+      "additionalProperties": {
+        "type": "object",
+        "properties": {
+          "command": {
+            "type": "array",
+            "items": { "type": "string" },
+            "description": "Command and arguments to start the LSP server"
+          },
+          "extensions": {
+            "type": "array",
+            "items": { "type": "string" },
+            "description": "File extensions this server handles (e.g., [\".ts\", \".tsx\"])"
+          },
+          "priority": {
+            "type": "number",
+            "description": "Server priority (higher = preferred)"
+          },
+          "env": {
+            "type": "object",
+            "additionalProperties": { "type": "string" },
+            "description": "Environment variables for the LSP server"
+          },
+          "initialization": {
+            "type": "object",
+            "description": "Custom initialization options"
+          },
+          "disabled": {
+            "type": "boolean",
+            "description": "Disable this LSP server"
+          }
+        }
+      }
+    },
     "claude_code": {
       "type": "object",
       "description": "Toggle Claude Code compatibility features on/off. All default to true (enabled).",