Move shared button, input, and listbox styles to a new formPrimitives module
used across admin panels, settings, and document settings. Update admin and
settings components to import these styles from the new location. Refactor
DocumentSelectionModal to use a direct files prop with loading and error
states, removing fetcher logic and internal fetch state. Add a custom hook
for library document queries. Clean up legacy admin/ui primitives and
standardize segmented controls and section layouts.
Add database-backed runtime configuration for feature flags and TTS provider credentials, editable via a new admin UI panel. Replace static NEXT_PUBLIC_* and TTS provider env vars with admin-managed settings stored in the database and injected at SSR for client access. Implement admin-only panels for managing shared TTS provider credentials (with encrypted API keys) and live site feature flags. Add schema migrations, API routes, React contexts, and hooks for SSR-injected runtime config and live updates. Update client and server logic to resolve configuration from the database at runtime, enforcing admin restrictions and supporting migration from legacy env-based config.
BREAKING CHANGE: Feature flags and TTS provider credentials are now managed at runtime via the admin UI. Environment variables are only used for initial seeding and are ignored after first boot. Existing deployments must migrate configuration to the admin panel.
