Replace color-only wiring/circuit instructions with redundant cues (a11y, WCAG 1.4.1) #111

Color-only wiring/circuit instructions (accessibility)

The V2.0 accessibility audit flagged color-only instructions in some wiring/circuit explanations — e.g. "connect the red wire to 5V and the black wire to ground" or diagrams that distinguish components by color alone. This fails WCAG 1.4.1 (Use of Color): users with color vision deficiency (or grayscale/printed copies) can't follow them.

Unlike the mechanical sweep in #110 (iframe title=, video aria-label, image alt), this needs content edits and isn't auto-detectable, so it's tracked separately.

What to do

• Audit wiring instructions and circuit diagrams for color-only cues.
• Add a redundant non-color cue: pin/row labels, position ("top rail"), shape, or text annotations alongside color.
• Prefer phrasing like "the red (positive) wire to 5V" so color is supplementary, not the sole signal.

Likely worst offenders (from the audit): electronics, cpx, sensors wiring sections. Needs a manual pass.

Part of V2.0.