Fix: Internal Server Error When Generating Data File for Restored Cases

[parthdagia05]

Bug Fix: Defensive Directory Creation for Data Generation 🛡️

Closes: #5

Summary

This PR resolves a 500 Internal Server Error that occurred when attempting to generate a data file for a restored case where the execution directory (res/<caserunname>/) was missing from the filesystem.

This ensures that the application remains resilient even if the metadata exists in resData.json but the physical directory structure was lost during a backup/restore cycle or manual cleanup.

---

Root Cause Analysis

The generateDatafile() method attempted to write a data.txt file directly to the path:
res/<caserunname>/data.txt

If the parent directory (<caserunname>/) did not exist, the operation would raise a FileNotFoundError, crashing the Flask route and returning an unhandled 500 error to the UI.

Typical Failure Scenario:

1. A case run is initialized, and metadata is saved to resData.json.
2. The system is backed up without the (empty) result directories.
3. The model is restored on a new machine.
4. Generating the data file fails because the expected directory path is missing.

---

Changes Implemented

1. Defensive Directory Provisioning

Added an idempotent directory check using pathlib before the file write operation:

os.makedirs(dataFilePath.parent, exist_ok=True)

[parthdagia05]

can anyone cross check this PR.