v0.7.1

[0.7.1] - 2026-06-03

• fix(ui): use theme color tokens in floating save button tint
• docs: finalize CHANGELOG for v0.7.1 [skip ci]
• chore: bump to 0.7.1
• chore: gitignore local .cargo/config.toml
• docs: add user guide site and keep-current workflow
• fix(ui): make canvas/shot color pickers color-space aware
• refactor(ui): collapse duplicated dialog-spawn and widget helpers
• fix(ui): pin prefs/shot row label column to a fixed width
• feat(ui): Export Shot tweak panel — live preview + art-direction knobs
• feat(io): Export Shot — polished social-media PNG (phase 1)
• docs: finalize CHANGELOG for v0.7.0 [skip ci]