Refactor app architecture and clean local artifacts

Backend/README.md

@@ -4,16 +4,33 @@
 
 The API targets PostgreSQL through EF Core 8 and `Npgsql.EntityFrameworkCore.PostgreSQL`.
 
-Default local development connection string:
+Local development is aligned with `../docker-compose.dev.yml` and `appsettings.Development.json`:
 
 ```text
-Host=localhost;Port=5433;Database=vtuber_star_awards_dev;Username=postgres;Password=postgres
+Host=localhost;Port=5433;Database=vtuber_star_awards_dev;Username=vtsa_dev;Password=change-me-local-only
 ```
 
-You can override it with:
+For production or shared deployments, keep checked-in appsettings empty and provide your own value through:
+
+```text
+VTSA_POSTGRES
+ConnectionStrings__Postgres
+```
+
+The API reads its connection string from:
 
-- `Backend/appsettings.Development.json`
 - environment variable `VTSA_POSTGRES`
+- environment variable `ConnectionStrings__Postgres`
+
+Presentation/demo data is controlled separately:
+
+```text
+VTSA_SEED_MODE=demo
+```
+
+- `demo`, `presentation` or `sample`: seed local presentation data.
+- `none`, `off`, `disabled` or an unset value in Production: do not seed presentation data.
+- `Backend/appsettings.Development.json` defaults to `demo`; `Backend/appsettings.json` defaults to `none`.
 
 If Docker is available locally, start a dev database from the repository root with:
 
@@ -51,20 +68,20 @@ dotnet ef database update
 Fallback bootstrap if `dotnet ef` is not usable in the current environment:
 
 ```bash
-psql "Host=localhost Port=5433 Database=vtuber_star_awards_dev Username=postgres Password=postgres" -f Migrations/InitialCreate.manual.sql
+psql "$VTSA_POSTGRES" -f Migrations/InitialCreate.manual.sql
 ```
 
 Run the API:
 
 ```bash
-ASPNETCORE_ENVIRONMENT=Development dotnet run
+ASPNETCORE_ENVIRONMENT=Development dotnet run --urls http://127.0.0.1:5084
 ```
 
 Check the API and database wiring:
 
 ```bash
-curl http://localhost:5084/api/health
-curl http://localhost:5084/api/health/database
+curl http://127.0.0.1:5084/api/health
+curl http://127.0.0.1:5084/api/health/database
 ```
 
 Development auth/session:
@@ -72,5 +89,27 @@ Development auth/session:
 ```bash
 curl -X POST http://localhost:5084/api/auth/dev-login \
   -H "Content-Type: application/json" \
-  -d '{"twitchUserId":"admin_demo","displayName":"Admin Demo","role":"admin"}'
+  -d '{"twitchUserId":"jayuhime_admin","displayName":"Jayuhime Admin","role":"admin"}'
 ```
+
+Demo admin login for public presentations:
+
+```text
+VTSA_DEMO_LOGIN_ENABLED=true
+VTSA_DEMO_ADMIN_LOGIN=jayuhime_admin
+VTSA_DEMO_ADMIN_EMAIL=admin@example.local
+VTSA_DEMO_ADMIN_PASSWORD=<set-secure-demo-password>
+VTSA_DEMO_ADMIN_TWITCH_ID=jayuhime_admin
+VTSA_DEMO_ADMIN_DISPLAY_NAME=Jayuhime Admin
+```
+
+The frontend route is `/login`. `VTSA_DEMO_ADMIN_LOGIN` may be a username or an email-style identifier; the backend also accepts the configured email, Twitch ID, and display name for admin flexibility. Disable the demo login for release with `VTSA_DEMO_LOGIN_ENABLED=false`.
+
+Frontend app-wide demo gate:
+
+```text
+VITE_DEMO_GATE_ENABLED=true
+```
+
+- `true`: the whole Vue app starts at `/login` until a session exists.
+- unset or `false`: public pages such as `/` are visible without the initial demo login.