chore(ui): eslint 10 (via jsx-a11y-x fork)

[thejefflarson]

Bumps ESLint 9 → 10 for the ui/ package. Supersedes Dependabot #102.

What changed

• eslint ^9.39.5 → ^10.7.0
• eslint-plugin-jsx-a11y ^6.10.2 → removed, replaced by eslint-plugin-jsx-a11y-x ^0.2.0
• @typescript-eslint/parser ^8.64.0 → ^8.65.0 (already eslint-10-compatible)
• eslint.config.js migrated to the fork's plugin key (jsx-a11y-x) and config accessor (configs.recommended.rules)

Why the plugin swap

The sole blocker to eslint 10 was eslint-plugin-jsx-a11y@6.10.2: it peer-caps eslint at ^9 and has no eslint 10 release (upstream PRs still open). I verified an npm overrides forcing the peer does work functionally on eslint 10, but chose the cleaner path: eslint-plugin-jsx-a11y-x@0.2.0, a maintained flat-config-native fork whose peer is eslint: ^9 || ^10. Its recommended ruleset is a superset of upstream's — every rule this gate relied on is present (now under a jsx-a11y-x/ prefix), plus label-has-for — so the JEF-431 a11y coverage is unchanged. typescript-eslint and eslint-plugin-react-hooks@7.1.1 already support eslint ^10.

Proof the a11y gate still fires (JEF-431)

A temporary bare-onClick <div> still errors on eslint 10:

jsx-a11y-x/click-events-have-key-events
jsx-a11y-x/no-static-element-interactions
✖ 2 problems (2 errors, 0 warnings)

Gates (all green, local)

• npm run lint — pass (clean on eslint 10.7.0)
• npm run build (tsc --noEmit && vite build) — pass
• npm test (vitest, incl. the axe route-smoke) — 14 passed
• npm ci — lockfile consistent (CI parity)

TypeScript 7 (#93) is intentionally NOT here

TS 7.0 GA ships the native/Go compiler without a stable programmatic API (that lands in TS 7.1), and typescript-eslint closed the TS-7.0 support request as not planned. I confirmed this empirically: forcing typescript@7.0.2 via an override makes @typescript-eslint/typescript-estree crash at lint time — TypeError: Cannot read properties of undefined (reading 'Cjs') (TS 7 dropped ts.Extension/ts.ModuleKind from its JS surface), which breaks the a11y lint gate. tsc --noEmit/build/test happen to pass under TS 7, but the lint gate does not, and there is no alternative type-aware linter. #93 is infeasible until TS 7.1 — not shipping a masked/broken bump. (Follow-up idea, separate ticket: keep TS 6.x and add @typescript/native-preview for a fast tsgo --noEmit.)

Closes #102

🤖 Generated with Claude Code

https://claude.ai/code/session_01JbrmfzHsTMMzPaSrUkZgWo