fix(a11y): compliance toggle knob position

[build-with-dhiraj]

What

Fixes the Compliance toggle knob geometry in the LabOS top nav. Follow-up to the focus-ring fix merged in #10; that PR cleaned the keyboard focus ring, this one corrects where the knob sits inside the track.

Root cause

In src/components/shell/ComplianceToggle.tsx, the switch knob span had a vertical anchor (top-0.5) but no horizontal anchor. With position: absolute and no left/right, left resolves to auto, placing the knob's base at the static-flow position (~14px, mid-track) instead of 0. The translate-x-* offsets were then applied on top of that wrong base.

Measured live before the fix:

• OFF (aria-checked=false): computed left: 14px + translate(2px) so knob.left - track.left = 16px. The knob sat on the right, so OFF read like ON.
• ON (aria-checked=true): computed left: 14px + translate(14px) so knob.left - track.left = 28px. Knob right edge at 770.66 vs track right 758.66, overflowing the 28px track by 12px (knob off the right edge, looks broken).

Fix (one line, ComplianceToggle.tsx only)

Add left-0 to the knob span so its base position is 0. Everything else is unchanged: track, colors, sizes, the translate-x-0.5 / translate-x-3.5 values, and the focus treatment from #10.

-          className={`absolute top-0.5 h-3 w-3 rounded-full bg-white ...
+          className={`absolute left-0 top-0.5 h-3 w-3 rounded-full bg-white ...

Verification (in-browser, Chromium via Playwright, against next dev)

After the fix:

• OFF (aria-checked=false): knob.left - track.left = 2px (knob at the LEFT), right-overflow 0. Computed left: 0px, transform: translate(2px).
• ON (aria-checked=true): knob.left - track.left = 14px (knob at the RIGHT, knob right edge 756.66 inside track right 758.66), right-overflow 0. Computed left: 0px, transform: translate(14px).
• Toggle flips correctly both ways; aria-checked and the persisted localStorage value track state (false/0 to true/1 to false/0).
• No console errors or warnings; no layout shift.

The pre-fix 16px / 28px-overflow numbers above were reproduced live in the same browser by removing the left-0 anchor, confirming the diagnosis.

CI parity

• npx tsc --noEmit: pass
• npm run build (Next build): pass, all 9 static pages generated, lint and type step clean
• Lint: this project has no separate eslint config or lint script; Next's build-time check passed.

No change to globals.css and no change to mcclean.ts.

🤖 Generated with Claude Code