feat(theme): Plan 2.5 P2 — Inter typography (AD-2.5-T1)

Per RFC-WS-PRIMEVUE-PLAN-2-5 §4 AD-2.5-T1. Establishes Inter as the
canonical Crewli body font via @fontsource/inter (local package, no
Google Fonts CDN).

Audit findings (pre-change):
- No @fontsource/public-sans package was installed.
- No <link> tag in index.html loaded Public Sans.
- Only one Public Sans reference existed in source: the vendored
  Vuexy SCSS variable $font-family-custom at
  src/@core/scss/template/libs/vuetify/_variables.scss, which drives
  Vuetify's $body-font-family on legacy surfaces during F4.
- No src/main.css exists; the Tailwind v4 entry lives at
  src/assets/styles/tailwind.css with no @theme block yet.

Changes:
- @fontsource/inter@^5.2.8 added to dependencies; weights
  400/500/600/700 imported at main.ts ahead of tailwind.css.
- src/assets/styles/tailwind.css: new @theme block declaring
  --font-sans Inter-first, plus :root --crewli-font-family and
  html/body font-family applying that variable cascade-wide.
- src/@core/scss/template/libs/vuetify/_variables.scss:
  $font-family-custom switched from the historical body font to
  Inter (vendored edit, narrowly scoped, F6 removes @core/ entirely).
- tests/unit/styles/typography.spec.ts: 3-spec regression lock
  (Tailwind direct stacks, Vuexy SCSS variable, zero historical
  references in either file). File-content inspection — jsdom does
  not cascade from imported stylesheets, so getComputedStyle would
  always pass.

Suite delta: 570 → 573 (+3; the prompt's template was +2 but the
audit revealed two distinct font-config files, so each gets its own
assertion per the prompt's "cover all sites" rule). vue-tsc clean.
Scoped ESLint clean.

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

apps/app/package.json

@@ -26,6 +26,7 @@
     "@casl/ability": "6.7.3",
     "@casl/vue": "2.2.2",
     "@floating-ui/dom": "1.6.8",
+    "@fontsource/inter": "^5.2.8",
     "@primeuix/themes": "^2.0.3",
     "@primevue/forms": "^4.5.5",
     "@sentry/vue": "10.52.0",