# Quick Sorter v1.5 — automatic collision resolution

V1.5 removes the manual collision-cleanup step from v1.4.

## Collision rule

When two confirmed files want the same target name, or the target already exists:

1. The sorter compares the **complete file contents with SHA-256**.
2. If they are byte-identical:
   - the already-existing / first planned copy is kept;
   - the redundant source is marked `EXACT → remove duplicate`;
   - it is deleted **only when you explicitly click Apply confirmed**.
3. If the bytes differ:
   - neither file is overwritten or deleted;
   - the incoming file is renamed automatically with a visible suffix such as
     `_variant-2`, `_variant-3`, etc.

Example:

```text
2026-09-01_cafe-bach_abrechnung.pdf
2026-09-01_cafe-bach_abrechnung_variant-2.pdf
```

## GUI

A new `Collision` column shows the resolution directly in the main table:

```text
EXACT → remove duplicate
DIFF → 2026-09-01_..._variant-2.pdf
```

You no longer need to deselect collision rows before Apply.

`Apply confirmed` gives one summary before touching disk:

- normal moves/renames
- different-content collisions kept as variants
- exact SHA-256 duplicates that will be removed
- unchanged files

## Important safety boundary

`EXACT` means **byte-for-byte identical** after a full-file SHA-256 comparison.
A PDF/DOCX that looks the same but has different embedded metadata is treated as
`DIFF` and kept as a variant. This is intentionally conservative.

Existing files are never overwritten.
Every Apply is logged in `.quick_sorter_log.csv`.