Fix feature pipeline status dark mode

[talissoncosta]

Problem

The entire release pipeline visualisation is broken in dark mode. White circles and grey lines render on a dark background, making the component unusable.

Files

• web/styles/components/_feature-pipeline-status.scss:2,4,16,20,30,39,43,52
• Hardcoded: white (bg), #AAA (border/bg), #6837fc (border), #53af41 (border/bg)

Solution

Add .dark overrides using semantic colour tokens from #6904.

Blocked by

• Introduce semantic colour tokens and primitive palette #6904 — Semantic colour tokens must land first

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Part of the Design System Audit (#6606) · Epic: #6882