Merge pull request #1131 from cx-alberto-simoes/feature/configurable-serena-folder-location

feat: add configurable project_serena_folder_location setting

Add a new `project_serena_folder_location` setting to `serena_config.yml` that allows configuring where the per-project `.serena` data folder (memories, caches) is stored, with `$projectDir` and `$projectFolderName` placeholder support (default: `$projectDir/.serena`, preserving current behavior).

Resolves #1123

Co-authored-by: Dominik Jain <dominik.jain@oraios-ai.de>

docs/02-usage/050_configuration.md

@@ -173,6 +173,35 @@ For advanced users, Serena's configuration can be further customized.
 The Serena user data directory (where configuration, language server files, logs, etc. are stored) defaults to `~/.serena`.
 You can change this location by setting the `SERENA_HOME` environment variable to your desired path.
 
+### Per-Project Serena Folder Location
+
+By default, each project stores its Serena data (memories, caches, etc.) in a `.serena` folder inside the project root.
+You can customize this location globally via the `project_serena_folder_location` setting in `serena_config.yml`.
+
+The setting supports two placeholders:
+
+| Placeholder          | Description                                     |
+|----------------------|-------------------------------------------------|
+| `$projectDir`        | The absolute path to the project root directory |
+| `$projectFolderName` | The name of the project folder                  |
+
+**Examples:**
+
+```yaml
+# Default: data stored inside the project directory
+project_serena_folder_location: "$projectDir/.serena"
+
+# Central location: all project data under a shared directory
+project_serena_folder_location: "/projects-metadata/$projectFolderName/.serena"
+```
+
+When a project is loaded, Serena uses the following fallback logic:
+1. Check if a `.serena` folder exists at the configured path.
+2. If not, check if one exists in the project root (default/legacy location).
+3. If neither exists, create the folder at the configured path.
+
+This ensures backward compatibility: existing projects that already have a `.serena` folder in the project root will continue to work, even after changing the `project_serena_folder_location` setting.
+
 (ls-specific-settings)=
 ### Language Server-Specific Settings