Fix Mermaid label contrast in dark mode

[thomhurst]

Summary

• restore Mermaid node-specific text colours in dark mode
• darken the highlighted initializer label to meet WCAG AA contrast

Root cause

The global dark-mode paragraph rule overrode colours inherited by Mermaid labels. This changed highlighted node text to #cbd5e1, producing contrast as low as 1.05:1 on pastel backgrounds.

The Mermaid-specific rule now preserves inherited node colours. The orange initializer label increases from 3.46:1 to 6.66:1 contrast.

Validation

• yarn build (docs)
• git diff --check
• contrast ratios checked for all three highlighted lifecycle nodes

Addresses discussion #6530.

[greptile-apps]

Greptile Summary

Updates the lifecycle documentation and dark-mode Mermaid styling to restore node-specific label colors and improve initializer-label contrast.

• Changes the initializer node text color from #e65100 to the darker #9a3412.
• Makes Mermaid node-label paragraphs inherit their node-specific text color in dark mode.

Confidence Score: 5/5

The PR appears safe to merge, with no concrete blocking or non-blocking defects identified in the changed code.

The CSS selector is more specific than the global dark-mode paragraph rule and is scoped to Mermaid node labels, while the documentation color adjustment improves contrast without changing diagram behavior.

Important Files Changed

Filename	Overview
docs/docs/writing-tests/lifecycle.md	Darkens the highlighted initializer node label while retaining the existing diagram structure and styling.
docs/src/css/custom.css	Adds a narrowly scoped dark-mode override so Mermaid node-label paragraphs inherit colors rather than receiving the global paragraph color.

_{Reviews (1): Last reviewed commit: "fix(docs): restore Mermaid label contras..." | Re-trigger Greptile}