build(deps): bump contentrain, vue, testing and linting groups

[ABB65]

Combines four Dependabot group bumps into one PR so CI runs once.

Bumps (package.json spec; lockfile resolved version in brackets where newer)

contentrain (#455)

• @contentrain/mcp 3.9.32 → 3.11.2
• @contentrain/query 7.6.38 → 7.6.45
• @contentrain/types 1.59.0 → 1.64.0

vue (#457)

• vue ^3.5.40 → ^3.5.43 (resolved 3.5.44)
• vue-router ^5.2.0 → ^5.4.0

testing (#458)

• @nuxt/test-utils ^4.0.3 → ^4.3.3
• @vitest/coverage-v8 ^5.0.1 → ^5.0.3 (resolved 5.0.4)
• @vue/test-utils ^2.5.0 → ^2.5.1
• happy-dom ^20.14.5 → ^20.14.6
• playwright-core ^1.63.0 → ^1.64.0 (resolved 1.64.1)
• vitest ^5.0.1 → ^5.0.3 (resolved 5.0.4)

linting (#459)

• @nuxt/eslint 1.16.0 → 1.17.0
• @commitlint/cli ^21.2.2 → ^21.2.3
• @commitlint/config-conventional ^21.2.2 → ^21.2.3
• eslint ^10.10.0 → ^10.12.0
• lint-staged ^17.5.1 → ^17.6.0

Lint fix

With @nuxt/eslint 1.17, vue/no-multiple-template-root rejects the comment at the template root of app/layouts/default.vue. The comment is moved inside the root <div>; no markup or behaviour change.

Local gates

• pnpm lint: 0 errors (7 existing warnings)
• pnpm typecheck: 0 errors
• pnpm test:unit: 200 files passed, 1 skipped; 2287 tests passed, 1 skipped
• pnpm test:integration: 54 files, 517 tests passed
• pnpm test:nuxt: 52 files, 358 tests passed
• e2e / RLS / contract suites left to CI

Supersedes #455 #457 #458 #459 (Dependabot will close them once main has these versions). #456 (nuxt 4.6) is left for its own PR: nuxt 4.6 template types no longer see auto-imports (TS2339 in ContentFieldEditor/Tooltip/ChatPanel…) and the contract suite fails to load .nuxt/tsconfig.app.json.

Label: GENERIC.