feat(context): add configurable memoryBoundaryMarkers setting (#24020)

docs/reference/configuration.md

@@ -1287,6 +1287,18 @@ their corresponding top-level category object in your `settings.json` file.
   - **Description:** Maximum number of directories to search for memory.
   - **Default:** `200`
 
+- **`context.memoryBoundaryMarkers`** (array):
+  - **Description:** File or directory names that mark the boundary for
+    GEMINI.md discovery. The upward traversal stops at the first directory
+    containing any of these markers. An empty array disables parent traversal.
+  - **Default:**
+
+    ```json
+    [".git"]
+    ```
+
+  - **Requires restart:** Yes
+
 - **`context.includeDirectories`** (array):
   - **Description:** Additional directories to include in the workspace context.
     Missing directories will be skipped with a warning.