(caching) Improve storage cache cleanup, do not clean very fresh files

We should not clean very fresh files, even we are short on disk space.
Also update README and add testpoint for token test

Signed-off-by: Denys Fedoryshchenko <denys.f@collabora.com>

Author: nuclearcat

README.md

@@ -45,6 +45,19 @@ JWT secret is configured in the `config.toml` file.
 ```
 This will generate a JWT token for the user.
 
+#### Testing Token Validity
+
+You can verify if a token is valid using the `/v1/checkauth` endpoint:
+
+```bash
+curl -X GET http://localhost:3000/v1/checkauth \
+    -H "Authorization: Bearer <JWT_TOKEN>"
+```
+
+**Responses:**
+- `200 OK` with body `Authorized: user@email.com` - Token is valid
+- `401 Unauthorized` with body `Unauthorized` - Token is invalid or missing
+
 ### Testing upload and download using curl
 
 ```bash

src/storcaching.rs

@@ -89,7 +89,14 @@ async fn clean_disk(cache_dir: String) {
             oldest_file = file;
         }
     }
-    delete_cache_file(oldest_file.file);
+    // if file is less than 60 min old, do not delete it
+    if oldest_file.last_update.elapsed().unwrap() > Duration::from_secs(60 * 60) {
+        delete_cache_file(oldest_file.file);
+    } else {
+        println!("File is less than 60 min old, skipping: {}, sleeping 60 seconds", oldest_file.file);
+        // sleep 60 seconds
+        tokio::time::sleep(Duration::from_secs(60)).await;
+    }
 }
 
 /// Cache housekeeping loop