[BUG] (Read-only file system) error when saving IPP job files on Android

[AshishYesale7]

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📝 Issue Description

Describe the bug:
When executing a print command from a remote client (e.g., macOS using lp), the Virtual Printer receives the IPP request but fails to save the job data due to a filesystem permission error:

❯ lp -h Android_OKAN6RTJ.local:3000 -d "Virtual_Printer_(CPH2381)" /Users/username/Downloads/extensions.txt
lp: No such file or directory

Debug Logs:

ACTION START IPP VIRTUAL PRINTER  
req:POST / from:fe80::1  
Failed to save IPP job:  
print_job_1745326755245.ipp: open failed:  
EROFS (Read-only file system)

Root Cause:
The IPP server attempts to write the job file using File(filename).writeBytes(buffer) in a directory where it doesn't have write permissions. Android sandboxing likely defaults to a read-only path in some contexts.

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✅ Suggested Fix

Use the app-specific storage directory (context.cacheDir or context.filesDir) for writing files instead of the default working directory.

Example fix:

val filename = File(context.cacheDir, "print_job_${System.currentTimeMillis()}.ipp")
filename.writeBytes(buffer)

📌 This will ensure the app writes to a valid path with permissions on Android devices.

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Let me know if you want help patching this or linking it with your Git commits!