Backend

File	Responsibility
`backend/src/main.ts`	Bootstraps Nest, middleware, OpenAPI, static assets, and SPA fallback.
`backend/src/app.module.ts`	Wires feature modules and global providers.
`backend/src/database/database.module.ts`	Configures TypeORM with SQLite.
`backend/src/database/database-init.service.ts`	Initializes the database and runs migrations.
`backend/src/common/guards/jwt-auth.guard.ts`	Global JWT authorization guard.
`backend/src/common/middleware/csrf.middleware.ts`	Double-submit CSRF protection.
`backend/src/common/services/event-status.service.ts`	Computes the event-window state machine.
`backend/src/common/services/sse-hub.service.ts`	In-process pub/sub for server-sent event streams.
`backend/src/modules/system/system.controller.ts`	Registers bootstrap, event status, settings, and SSE endpoints.
`backend/src/modules/system/system.service.ts`	Builds the public bootstrap payload.
`backend/src/modules/auth/auth.controller.ts`	Registers authentication and account endpoints.
`backend/src/modules/auth/auth.service.ts`	Handles sessions, authentication, registration, and password changes.

Frontend

File	Responsibility
`frontend/src/main.ts`	Bootstraps Angular and registers HTTP interceptors.
`frontend/src/app/app.routes.ts`	Defines public, shell, child, and admin routes.
`frontend/src/app/app.component.ts`	Loads bootstrap data and restores the session.
`frontend/src/app/features/home/home.component.ts`	Authenticated shell container; starts user and event state services.
`frontend/src/app/core/services/auth.service.ts`	Signal-backed access token and current-user state.
`frontend/src/app/core/services/authenticated-event-source.service.ts`	Fetch-based authenticated SSE transport with frame parsing and abort support.
`frontend/src/app/core/services/event-status.store.ts`	Event state signal store and one-second countdown timer.
`frontend/src/app/core/services/event-status.pure.ts`	Event payload types, pure countdown helpers, and the `LED_COLOR_BY_STATE` map used by the shell LED.
`frontend/src/app/features/shell/header/shell-header.component.ts`	Shell title, status LED (size/shape only — color comes from the pure map via `[style.background-color]`), countdown, and user menu.
`frontend/src/app/features/shell/tabs/quick-tabs.component.ts`	Main shell navigation tabs.
`frontend/src/app/features/shell/change-password/change-password-modal.component.ts`	Change-password form modal.
`tests/frontend/authenticated-event-source.spec.ts`	Tests SSE authorization and frame transport behavior.