Locale-Prefixed Routing

With prefix_except_default, German URLs live under /de/… while bare paths resolve to the default locale (English). Any navigation or path check that assumes an unprefixed path silently resets a non-English session.

The rule

Never match or build an /app/…, /login, or /register path without accounting for the locale prefix.

• Matching: strip the prefix first with stripLocalePrefix() from #layers/BaseShared/utils/locale. Three route middlewares were bitten by this: 01.auth.global (logged-in users saw /es/login), 02.admin.global (admin guard bypassed under /de/app/admin), and 03.business-check.global (business setup skipped on every prefixed route).
• Linking: build targets with useLocalePath() — sidebar links, redirect pages, dashboard quick actions. A bulk localize() pass over a menu array beats editing dozens of to: lines; it passes through already-prefixed, external, and non-string targets untouched.

Why it hid so long

English (the default) is never prefixed, so every path check and every link works perfectly until someone switches language. The calendar exposed it first because its entry points (/app/calendar links + legacy redirects) are pure navigation with no other logic to blame.

Checklist for new routes

1. Links: localePath('/app/…'), never a bare string.
2. Middleware guards: compare stripLocalePrefix(to.path).
3. Redirect targets: navigateTo(localePath('…')), stripping first if the source path may already carry a prefix.
4. updateQueryParams-style query-only pushes are safe — they keep the path.