feat: config system

[IdrisGit]

• Added schema-driven config support with Zod, including defaults, event-level overrides, and strict validation/loading.
• Updated runtime notification scheduling to use resolved config values (enabled + delay per event), with config errors surfaced via TUI toast.
• Added versioned JSON schema generation ($id on unpkg), included editor $schema support, and wired publish flow to regenerate schema/build via prepack with early duplicate-version checks in release CI.