Description

All packaging artifacts live under packaging/ (chocolatey, nix, winget) except aur/, which sits at the repo root. Move it for consistency.

While at it:

• Update the static PKGBUILD reference file to the current release (v0.2.0, currently pinned to v0.1.0)
• Remove the dead sed 's/^ //' line from the update-aur CI job (same no-op bug fixed for Nix/Scoop in PR feat(packaging): add Nix derivation and flake #56 — the heredoc uses a quoted delimiter <<'PKGEOF' so YAML indentation stripping never runs)

Acceptance Criteria

• aur/PKGBUILD moved to packaging/aur/PKGBUILD
• packaging/aur/PKGBUILD updated to v0.2.0 hashes
• Dead sed line removed from update-aur CI job in release.yml
• No other files require changes (CI generates PKGBUILD inline and never references the repo file)

Notes

• release.yml update-aur job generates PKGBUILD entirely from a heredoc — it does not read aur/PKGBUILD. Moving the file has zero CI impact.
• The dead sed is on line 292 of release.yml: sed -i 's/^ //' PKGBUILD