v0.3.0

• Keyboard navigation: ← / → move left and right columns. Diff viewer is scrollable by keyboard. You can press ⏎ Enter to submit a commit. ␛ Escape undoes a commit.
• Tags: Add / remove and view tags on a commit.
• Discarding changes on a file now move that file to the Trash so it can be retrieved if needed.
• Success toast: uses .glassEffect rather than trying to reproduce it.
• Image comparison: images are correctly masked.
• Optimisation: cleaned up concurrency & deprecation warnings.