feat: add CUSTOM_PATH environment variable for dynamic storage paths

apps/docs/content/docs/3.2-beta/manual-installation.mdx

@@ -201,6 +201,17 @@ You should see the full Palmr. application ready to go!
 
 This guide sets up Palmr. using the local file system for storage. Want to use an S3-compatible object storage instead? You can configure that in the `.env` file. Check the Palmr. documentation for details on setting up S3 storage just update the environment variables, then build and run as shown here.
 
+### Custom Installation Paths and Symlinks
+
+If you're using a custom installation setup with symlinks (for example, `/opt/palmr_data/uploads -> /mnt/data/uploads`), you might encounter issues with disk space detection. Palmr. includes a `CUSTOM_PATH` environment variable to handle these scenarios:
+
+```bash
+# In your .env file (apps/server/.env)
+CUSTOM_PATH=/opt/palmr_data
+```
+
+This tells Palmr. to check your custom path first when determining available disk space, ensuring proper detection even when using symlinks or non-standard directory structures.
+
 ---
 
 ## Command cheat sheet

apps/docs/content/docs/3.2-beta/quick-start.mdx

@@ -166,6 +166,7 @@ Customize Palmr's behavior with these environment variables:
 | `ENCRYPTION_KEY`                | -          | **Required when encryption is enabled**: 32+ character key for file encryption                                         |
 | `DISABLE_FILESYSTEM_ENCRYPTION` | `true`     | Disable file encryption for better performance (set to `false` to enable encryption)                                   |
 | `PRESIGNED_URL_EXPIRATION`      | `3600`     | Duration in seconds for presigned URL expiration (applies to both filesystem and S3 storage)                           |
+| `CUSTOM_PATH`                   | -          | Custom base path for disk space detection in manual installations with symlinks                                        |
 | `SECURE_SITE`                   | `false`    | Enable secure cookies for HTTPS/reverse proxy deployments                                                              |
 | `DEFAULT_LANGUAGE`              | `en-US`    | Default application language ([see available languages](/docs/3.2-beta/available-languages))                           |
 | `PALMR_UID`                     | `1000`     | User ID for container processes (helps with file permissions)                                                          |

apps/server/src/env.ts

@@ -33,6 +33,7 @@ const envSchema = z.object({
     .string()
     .optional()
     .transform((val) => (val ? parseFloat(val) : undefined)),
+  CUSTOM_PATH: z.string().optional(),
 });
 
 export const env = envSchema.parse(process.env);

apps/server/src/modules/storage/service.ts

@@ -284,7 +284,7 @@ export class StorageService {
   private async _getDiskSpaceMultiplePaths(): Promise<{ total: number; available: number } | null> {
     const basePaths = IS_RUNNING_IN_CONTAINER
       ? ["/app/server/uploads", "/app/server/temp-uploads", "/app/server/temp-chunks", "/app/server", "/app", "/"]
-      : [".", "./uploads", process.cwd()];
+      : [env.CUSTOM_PATH || ".", "./uploads", process.cwd()];
 
     const synologyPaths = await this._detectSynologyVolumes();