User Profile Quick-View: reusable dialog for viewing any user

[Flo0806]

Description

Anywhere a user avatar or name appears (inbox cards, issue timeline, reviewer/assignee badges, comment authors, repo owner chips, etc.), clicking it should open a profile quick-view dialog — not navigate away.

The core component (UserProfileCard) must be reusable: works inside a UModal/USlideover now, embeddable in a dedicated page later.

Implemented

Core

• UserProfileCard.vue — self-contained, takes login: string as prop, fetches own data
• UserProfileDialog.vue — wraps card in UModal, triggered via useUserProfileDialog().open(login)
• GET /api/user/profile?login={username} — aggregates profile + top repos, Nitro-cached

Profile data shown

• Avatar, display name, login
• Bio, company, location, website/blog, Twitter/X
• Followers / Following / Public repos counts
• Top 6 repositories (stars, language, fork badge)
• Member since (account creation date)
• Direct link to GitHub

Contribution graph (bonus, originally #40)

• GET /api/user/contributions — GitHub GraphQL API, 30min cache
• ContributionGraph.vue — HTML CSS Grid heatmap, 365 days
• 3 switchable skins: default (primary color), grass (earth + blades), fire (flames + sparks)
• Skin persisted in user settings, cycle button in graph header + settings page

Infrastructure

• Caching via defineCachedFunction (30min)
• i18n keys for all strings (en + de)

Out of scope (moved to #149)

• Pronouns display
• Status emoji + message (reuse existing StatusBadge)
• Profile README rendering
• Shared repos (repos you both contribute to)
• Recent activity summary
• Clickable everywhere (wire dialog into all avatar/name occurrences)
• Reusable UserChip.vue component