feat: add eslint v10 support

[nicola-smartive]

• Relax peer eslint to ^9.22.0 || ^10.0.0 and bump dev eslint → 10.3.0 / @eslint/js → 10.0.1.
• Bump @typescript-eslint/* to ^8.59.2 (declares eslint v10 peer) and eslint-plugin-react-hooks to ^7.1.1 (declares eslint v10 peer).
• Tighten engines to ^20.19.0 || ^22.13.0 || >=24 to match eslint v10's engines.node.
• Restructure configs.ts for eslint v10's stricter plugin-rule validation:
  • Split typescriptRules into a new tsBaseConfig block scoped to **/*.{ts,tsx,mts,cts}, where the @typescript-eslint plugin is actually registered.
  • Scope the flatConfigNext rules-only block and reactConfig to the same file globs.
  • Explicitly register @typescript-eslint plugin in flatConfigNext since eslint-config-next only registers it for **/*.{ts,tsx} — rules referenced elsewhere now resolve.
• Add overrides to satisfy outdated v9-capped peer ranges of eslint-plugin-import (^2.32.0, peer caps at eslint v9) and eslint-plugin-react (^7.37.5, peer caps at eslint v9.7), both of which still work at install time once the peer is overridden.

Blocked at runtime — DOES NOT make consuming projects pass eslint against v10 yet:

• eslint-plugin-react@7.37.5 (latest) still calls removed eslint v9 context APIs (context.getFilename() / context.getSourceCode()) in three spots that bypass the plugin's own compat helpers:
  • lib/util/version.js:31
  • lib/rules/jsx-filename-extension.js:64
  • lib/rules/forward-ref-uses-ref.js:60 Upstream fix is Fix ESLint v10 RuleContext API removal (follow-up to #3972) jsx-eslint/eslint-plugin-react#3979 (open since Feb 2026, stalled on contributor inactivity). Tracking issue: ESLint v10 compatibility jsx-eslint/eslint-plugin-react#3977 (248+ 👍).
• eslint-config-next (incl. canaries) still depends on the broken eslint-plugin-react@^7.37.0 and Vercel has explicitly deferred their own switch in favour of waiting for upstream — see [ESLint v10]: TypeError: contextOrFilename.getFilename is not a function when running ESLint v10 vercel/next.js#89764 and the closed-without-merge attempt in fix : add ESLint v10 support to eslint-config-next vercel/next.js#91710.

Consumers upgrading to eslint v10 today need a patch-package shim over eslint-plugin-react (≈3 lines) until upstream lands. This package is ready for v10 but is gated by that upstream fix.