fix: handle edit intents without output URI

[naveensingh]

Type of change(s)

• Bug fix
• Feature / enhancement
• Infrastructure / tooling (CI, build, deps, tests)
• Documentation

What changed and why

• Updated the condition that prevented edit intents without an output URI. The app will display the usual save dialog when this happens (as opposed to overwriting the original file).

Closes the following issue(s)

• Closes edit link from fossify gallery open blank page. #76

Checklist

• I read the contribution guidelines.
• I manually tested my changes on device/emulator (if applicable).
• I updated the "Unreleased" section in CHANGELOG.md (if applicable).
• All checks are passing.