[Feature] Add PDF and DOCX export options for analysis reports

[Void-Anvesha]

Summary

The application currently allows users to download analysis results only as a .txt file. Add export options for PDF and DOCX formats.

Steps To Reproduce

1. Run a code analysis.
2. Click the download button.
3. Observe that the report downloads only as a .txt file.

Expected Behavior

Users should be able to choose an export format:

• TXT
• PDF
• DOCX

Actual Behavior

Only a plain-text .txt report can be downloaded.

Environment

• OS: Windows
• Browser: [add browser/version]
• Python version: [add version

[umang24-cyber]

@imDarshanGK , I would like to work on this issue under GSSOC'26 , please assign this to me!! /assign