v0.6.0 · GUI overhaul: quality metrics, presets, sortable table & native AVIF EXIF

One of the biggest byteshaver-gui update so far: six planned workstreams plus two
community-feedback rounds turn the GUI into a proper conversion workbench —
with compression-ratio feedback, perceptual quality metrics, presets, and a
fully reworked file table. On the CLI side, AVIF outputs now embed EXIF
natively.

✨ Highlights

• Quality measurement — right-click any converted file to measure DSSIM
  and PSNR (memory-bounded, computed off-thread), or open the visual
  difference inspector: side-by-side, swipe and amplified-difference
  heatmap views with synchronized zoom.
• Presets — save your target-format + policy combinations as
  shareable files (title & description included), or start from built-in,
  literature-based profiles for AVIF, WebP, JPEG XL and oxipng.
• File table — sortable columns, drag-to-reorder headers, configurable
  data fields (modified date, dimensions, EXIF camera/date-taken/ISO/
  exposure), target-format column, per-row "open converted file" /
  "open output folder" actions, and optional thumbnails.
• Progress that tells the truth — a segmented bar shades finished files
  by their result and animates only the files currently being worked on;
  a successful, size-saving run earns a compression-ratio-scaled confetti
  burst right on the converted rows 🎉 (configurable, reduced-motion aware).
• Native AVIF EXIF — avif targets embed EXIF via ravif ≥ 0.13 as a
  standard HEIF Exif item; the "metadata dropped" warnings for avif are gone.

🖥️ Desktop GUI

• Compression ratio with subtle color hints in rows, footer and report
• Options UX: quality-ladder chips (⚡ speed / ▤ size) per encoder, aligned
  option form, restore-defaults with undo, auto-sizing options panel that
  hands space back to the file table when collapsed
• Independent OS windows: run report, about, difference inspector and the
  preset windows can be dragged outside the main window; the report window
  resizes properly and remembers its geometry
• Windows integration: "show in folder" selects the written file (paths
  with spaces fixed), drag-and-drop unchanged
• Output handling: "same as input" ↔ "directory:" toggle keeps your path,
  an empty directory is a start blocker instead of writing silently,
  state-colored Convert button

🧩 CLI & core

• avif: EXIF embedding (follows the global --exif policy; pixels unaffected)
• Job API: Outcome::Encoded/SkippedExisting now carry output_path
  (front-ends can open/reveal results); new public helpers
  input::decode_rgba and the typed ExifSummary reader
• Encoder capability descriptions are identity-only; the option detail
  stays in the per-run "Using …" line

⚠️ Compatibility notes

• JSON-lines event logs gain an output_path field (additive — existing
  parsers unaffected)
• GUI settings.json migrates automatically (output mode is now explicit;
  old flat and embedded layouts both load)
• New GUI-only dependencies (egui_extras, image, dssim) are pure Rust;
  the static musl / windows-gnu release builds are unchanged

📦 Artifacts

As always: CLI and GUI binaries for Linux (musl, static-pie) and
Windows per CPU target (x86-64-v3/v4) with .sha256
checksums; docker images (alpine + debian) with HEIC/HEIF/AVIF input support.