b3bde0d896
Two related parity gaps from the VanillaJS → Svelte migration (issue #500): internal-vs-external users weren't badged, and external users in a share's member list rendered as a bare UUID with a static icon — no avatar, no email. Both share one root cause: there was no shared user vignette and no resolver for non-directory (external) users (the system address book lists internal users only, and ShareDialog hardcoded isExternal=false). - lib/api/endpoints/users.ts: resolveUser(id) — cached GET /api/users/{id} (the authenticated per-user profile lookup) → {name, email, image, isExternal}; returns null when the profile isn't visible so callers keep their fallback label. - lib/components/UserVignette.svelte: reusable identity chip — avatar (photo or coloured initials), name, email, and a building-circle-xmark badge for external users; resolves lazily and falls back to a caller-supplied label. - lib/utils/avatar.ts: userInitials() + avatarColorIndex() extracted from AppShell (now shared by both — no duplicated logic) so vignette and account button render identically. - ShareDialog: user member rows now render <UserVignette>; groups keep their icon+label. Drops the dead hardcoded isExternal. Backend already exposes everything (UserDto.email/image/is_external via GET /api/users/{id}); no backend change. Frontend gate green (svelte-check 0/0, eslint, stylelint, prettier) + 47 Vitest. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>