ci: fxcss 0.20.0 — the audit stops guessing across documents

[adamXbot]

Bumps the three FXCSS_VERSION pins to 0.20.0, which carries two selector-audit fixes that change what the weekly watch reports about this theme.

What 0.20.0 fixes

AdamXweb/fxcss#24 — a name Firefox ships outranks one it merely resembles. The shipped-chrome pack was consulted last, after both fuzzy matchers, so a token Firefox ships under its own spelling could be reported as a typo for an unrelated live element. It now outranks them.

AdamXweb/fxcss#25 — a rule scoped to another document is not judged by this window. The audit had no @-moz-document handling at all: extraction was scope-blind, so every token was compared against DOM collected only from the main browser window. Tokens now carry the binding they were written under.

Together those retire the #placesToolbar finding, which was never a theme bug. #placesToolbar is the Library window's toolbar (places.xhtml:1154), and our rule is correctly inside @-moz-document url("chrome://browser/content/places/places.xhtml") at parts/places.css:107. The audit was proposing #PlacesToolbar — the main window's bookmarks toolbar, browser.xhtml:6472. Applying it would have moved Library styling onto the bookmarks bar.

0.20.0 also fixes fxcss upgrade --audit counting offscreen findings as upgrade blockers, the inverse of the --strict test — it would have started refusing upgrades over names Firefox still ships.

Measured on this branch, Firefox 153

Running the exact line firefox-watch.yml uses:

tree	result
master + 0.19.0	exits 1, 2 findings, one of them the harmful #placesToolbar rename
master + 0.20.0 (this PR)	exits 1, 1 finding — #private-browsing-indicator-with-label
this PR + #221	exits 0, empty patch

So this PR alone does not silence the watch: it removes the wrong recommendation, and #221 removes the last real one. Both are needed, and they touch different files (workflows vs CSS) so they do not conflict.

Why an in-place bump rather than fxcss init --force

Nothing in the workflow templates changed in 0.20.0, and regenerating would drop the publish allowlist entries this repo deliberately keeps ahead of them.

🤖 Generated with Claude Code

[github-actions]

Theme preview

Rendered from 3fb288e against the base branch.

Linux — no visual change

Nothing rendered differently. Current appearance:

macOS — no visual change

Nothing rendered differently. Current appearance:

Windows — no visual change

Nothing rendered differently. Current appearance:

No pixel differences on any platform — this PR does not change how the browser chrome renders in these views.

_{Views: browser window, focused address bar, find bar, modal dialog — each in light and dark. Native popups (app menu, context menus) are OS-level windows and cannot be captured. Workflow run}