fix: override global .hidden utility with !important on exposure dropdown variants

fix: exposure dropdown visibility — hidden level no longer invisible; each option shows its own color

fix: register installed skills as tools in config so exposure changes persist and survive refresh; replace exposure cycle badge with dropdown

feat: 3-level exposure — primary (full schema), secondary (name-only), hidden (search-only)

feat: AuroraCoder-styled management UI, light mode default, auth fix

feat: add skill support to server + skill publish CLI command

feat(management): add store exposure, file browser, skill folder scanning, MCP folder lifecycle

fix(management): shift UI from 'create from scratch' to 'connect to existing / register from file'

feat(management): add local management server + SPA for MCP servers, skills, and tool exposure