Add QR code sharing for URL profiles - #850

Adds Share QR code directly below Duplicate in the profile menu for imported URL profiles. Selecting it displays the original profile URL in a Material dialog that matches the existing UI.

QR codes are generated locally off the UI thread with UTF-8 support. Links exceeding QR capacity show an error message. The new strings cover every existing app locale, and the dialog closes when the activity is destroyed.

Validation:

• Built :app:assembleMetaDebug successfully for all four supported architectures.
• Verified the APK signature and all eight locale variants of the new strings.
• Checked QR round trips for ordinary URLs, escaped query parameters, and Unicode, plus oversized-link rejection.
• Installed the arm64 debug APK on a Xiaomi phone and verified menu placement, localized text, dialog dismissal, and decoding of the displayed QR code to the exact original URL.
• User confirmed the feature works on the phone.
• git diff --check passed.

Screenshots

Screenshots from the tested arm64 debug build. The QR code contains a local test-profile URL.

Profile menu	QR code dialog