fix(hud): strict-undefined in SegmentedRing instance-matrix loop

`initialMatrices[i]` is provably defined because the loop bound is
`i < tickCount` and `initialMatrices.length === tickCount`. TS doesn't
track that, so use a non-null assertion to silence TS18048.

The other ~30 errors reported in CI run 25797533005 were all downstream
of `TS2307: Cannot find module '@jarvis/bus'` — they disappear once
`pnpm install` + `bash scripts/build-webview.sh` generates the bus
package's `dist/index.d.ts`. No code change needed for those.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

webview/packages/hud/src/hud/SegmentedRing.tsx

@@ -88,7 +88,7 @@ export function SegmentedRing({
 
     if (!appliedRef.current) {
       for (let i = 0; i < tickCount; i++) {
-        const m = initialMatrices[i]
+        const m = initialMatrices[i]!
         tmpMatrix.compose(m.pos, m.quat, m.scale)
         meshRef.current.setMatrixAt(i, tmpMatrix)
       }