Move layer-wrapper out of gauge SDC, add gauge-popover library

[jjroelofs]

Summary

• Move the layer-wrapper gin-layer-wrapper div out of the analyze:gauge SDC into the analyze-gauge.html.twig theme template, so the SDC is a pure reusable component without Gin-specific markup
• Add analyze.libraries.yml with a gauge-popover library providing CSS overrides (overflow, padding) for rendering the gauge inside the views_color_scales popover container
• Required by Add on-hover scale popover to color-scaled values views_color_scales#4 (scale popover decoupling)

Test plan

• Verify gauges on analyze detail pages still render correctly with the layer-wrapper
• Verify popover gauges in all four Views report pages show range labels without clipping
• Verify dark mode rendering is unaffected

[jjroelofs]

The refactoring itself is clean: the layer-wrapper moves to the right layer and the SDC becomes a reusable pure component. One concern about dead code.

Findings

Medium: gauge-popover library appears unused and duplicates existing CSS

analyze.libraries.yml defines a gauge-popover library, but nothing attaches it: not this PR, not views_color_scales#4, and not the downstream analyze_ai_* PRs (brand_voice#18, content_marketing_audit#19, content_security_audit#17, sentiments#31). The CSS rules in css/gauge-popover.css (.vcs-popover .analyze--gauge { overflow: visible; padding: 0 2rem; }) are a subset of what the views_color_scales:scale_popover component CSS already provides (which adds margin: 0 on top). The .vcs-popover selector also couples this module to a class defined by views_color_scales.

Is this library intended for a consumer that does not yet exist? If so, consider adding a code comment noting the intended use case. If it was meant to be attached by VCS, it is redundant with the scale_popover component styles.

Verified

• The rendered output of #theme => 'analyze_gauge' is structurally identical before and after (the wrapper div still appears via the theme template).
• VCS PR 4 renders via #theme => 'analyze_gauge', so the layer-wrapper is still present inside the popover; VCS already styles both .vcs-popover .layer-wrapper and .vcs-popover .analyze--gauge.
• SDC prop types are unchanged; value remains typed as number in gauge.component.yml.
• The {% embed %} in analyze-gauge.html.twig passes all eight required props from the theme variables.

Nits

• components/gauge/gauge.twig and templates/analyze-gauge.html.twig both lack a trailing newline (pre-existing, not introduced by this PR, but easy to fix while editing).

[jjroelofs]

Re-review (round 2)

Verdict: No blockers remaining. Previous medium finding is resolved by downstream context; new commit is correct.

Previous findings

1. Medium (library never attached / CSS duplication): Resolved. The gauge-popover library is designed to be attached by downstream consumers via hook_views_color_scale_popover_alter(); confirmed in analyze_ai_sentiments#31 and analyze_ai_brand_voice#18, which both include 'library' => ['analyze/gauge-popover'] in their #attached arrays. The CSS is complementary, not duplicated: scale_popover.css defines the popover container; gauge-popover.css adjusts the gauge inside it.

   One residual note (low): gauge-popover.css targets .vcs-popover, a class owned by views_color_scales. If that class name changes upstream, this CSS breaks silently. Acceptable for co-maintained modules; just worth knowing.

2. Nit (missing trailing newlines): Still present. Both components/gauge/gauge.twig and templates/analyze-gauge.html.twig end without a final newline (\ No newline at end of file in the diff).

New commit: "Remove caption top margin in popover gauge for uniform spacing"

Correct. The gauge SDC defines caption { margin: 0.5rem 0; } in gauge.css. The new rule:

.vcs-popover .analyze--gauge caption {
  margin-top: 0;
}

Zeroes out the top margin specifically inside the popover context, giving tighter spacing. Specificity is sufficient (two classes + element vs one class + element in the base rule).

Alter hook integration

No action needed from the analyze module itself. The views_color_scales PR #4 exposes hook_views_color_scale_popover_alter(), which the downstream analyze_ai_* modules implement. The analyze module's role is to provide the gauge SDC and the gauge-popover library; both are present and correctly structured.

[jjroelofs]

All review findings addressed. LGTM.