Convert mastodon flavour SCSS to CSS custom properties (Phase 7)

Replace $var with var(--var) across all 23 mastodon/*.scss files + mailer.scss.
Inline avatar/search mixins, unroll @each/@for, hardcode hex-color() in data URIs.
Merge pre-calculated properties into variables.scss :root blocks for all 3 themes.
Fix theme import order, delete _mixins.scss and temporary properties files.

Convert glitch component SCSS to CSS custom properties (Phase 5+6)

Replace $var with var(--var), inline all mixins, unroll @each/@for,
convert color functions to pre-calculated properties. Merge properties
into variables.scss :root blocks, fix theme import order for CSS cascade.

Convert 17 SCSS files to CSS custom properties (Phase 3-4)

Replace $variables with var(--custom-properties), pre-calculated
color functions with themed custom properties, and unroll Sass
control flow (@each, @for, @extend) into plain CSS. Files keep
.scss extension during transition as index.scss still imports them.

Build: split CSS/SCSS webpack rules + generate CSS custom properties

- Split webpack css rule into separate .css and .scss rules so pure
  CSS files skip sass-loader (Phase 1)
- Generate properties.css for dark/light/contrast themes with all
  pre-calculated color values as CSS custom properties (Phase 2)
- Add extract-colors.js helper script for color value generation

Fix merged PR bugs and rewrite reduced-motion to pure CSS

- PR #64: fix typo "ad" → "add" in bookmark folder empty message
- PR #64: fix reducer using wrong key ('folder'/'title' → 'name')
- PR #84: implement confirm_unfollow using local_settings instead of
  server-side unfollowModal global
- PR #104: replace JS body-class approach with native CSS
  @media (prefers-reduced-motion) queries across all SCSS files
- Wide view: columns fill available space, content centered at 600px

Cherry-pick PR #104: Reduced motion accessibility

Adds prefers-reduced-motion support via JS body class detection and
CSS animation gating. Will be rewritten to pure CSS approach.

From: Moiety (https://codeberg.org/superseriousbusiness/masto-fe-standalone/pulls/104)

Merge PR #84: Confirmation dialogs

Adds local settings to toggle confirmation dialogs for boost, favourite,
delete, and unfollow actions. Replaces server-side boostModal/deleteModal
globals with client-side local_settings.

From: Ittihadyya (https://codeberg.org/superseriousbusiness/masto-fe-standalone/pulls/84)

Merge PR #64: Bookmark folders

Adds bookmark folder support: create/manage folders, assign bookmarks
to folders, browse bookmarks by folder. Also refactors alert/toast
system to support clickable actions.

From: mkljczk (https://codeberg.org/superseriousbusiness/masto-fe-standalone/pulls/64)

[build] upgrade eslint to 9.37.0 (#88)

Co-authored-by: tobi <tobi.smethurst@protonmail.com>
Reviewed-on: https://codeberg.org/superseriousbusiness/masto-fe-standalone/pulls/88
Co-authored-by: Zoë Bijl <moiety@noreply.codeberg.org>
Co-committed-by: Zoë Bijl <moiety@noreply.codeberg.org>

[feature] decouple login.scss from variables (#93)

Preparing for a switch to CSS variables

- decouple login.scss from variables.scss
- move scrollbar css to separate file

Reviewed-on: https://codeberg.org/superseriousbusiness/masto-fe-standalone/pulls/93
Co-authored-by: Zoë Bijl <code@moiety.me>
Co-committed-by: Zoë Bijl <code@moiety.me>

[bugfix] correct import of `@rails/ujs` / fix lint issues (#92)

Details: https://github.com/rails/rails/issues/49768
Reviewed-on: https://codeberg.org/superseriousbusiness/masto-fe-standalone/pulls/92
Co-authored-by: Zoë Bijl <code@moiety.me>
Co-committed-by: Zoë Bijl <code@moiety.me>

made fav & delete dialogs work on detailed posts – apparently i forgot to properly reference 'settings', now i feel really stupid :3

minor formatting fix

remove import of no import(ance)

reorder defaults and add default for favourite confirmation

implement functionality for favourite confirmation

favorite -> favourite, not sure if that's the preferred form but i've seen a lot more written that way within the repo, altho this is trivial to change. also added the string for translation

reordered settings in order of \'severity\' \(unfollow, delete, boost, fav\) and added the setting to allow confirmation of favorites

Implemented functionality for the setting governing delete confirmation dialogs

fix typo and reword setting to be consistent with \'confirm_VERB\'