Close OSS self-host gaps: in-repo API docs, legal notes, and packaging.

Add MIT license and docs/api, strip SaaS status/admin remnants from robots and footer, align env/compose/README with payment-free product truth.

.env.example

@@ -1,19 +1,23 @@
-# Songs2VID OSS is always self-hosted and has no billing configuration.
+# Songs2VID OSS is always self-hosted and payment-free.
+# Do not set Stripe, billing, credits, pricing, or S2VID_EDITION variables — they are unused.
+
+# --- Required ---
 DATABASE_URL="postgresql://songs2vid:songs2vid@localhost:5433/songs2vid"
 REDIS_URL="redis://localhost:6380"
 NEXTAUTH_URL="http://localhost:3000"
 NEXTAUTH_SECRET="replace-with-a-long-random-secret"
-# Optional; falls back to NEXTAUTH_SECRET.
-# TOKEN_ENCRYPTION_KEY="replace-with-another-long-random-secret"
 
 GOOGLE_CLIENT_ID="your-google-client-id.apps.googleusercontent.com"
 GOOGLE_CLIENT_SECRET="your-google-client-secret"
+
+# --- Optional ---
+# TOKEN_ENCRYPTION_KEY="replace-with-another-long-random-secret"  # falls back to NEXTAUTH_SECRET
 UPLOAD_DIR="./uploads"
+# FFMPEG_PATH="C:/path/to/ffmpeg.exe"   # override bundled / image ffmpeg
+# S2VID_PORT=3000                       # host port for docker-compose.yml (default 3000)
+# S2VID_IMAGE_TAG=latest                # Docker Hub tag when using published image
 
 NEXT_PUBLIC_DOCS_URL="https://docs.songs2vid.com"
 NEXT_PUBLIC_GITEA_ISSUES_URL="https://git.atakanozban.com/Songs2VID/songs2vid/issues"
 NEXT_PUBLIC_GITEA_URL="https://git.atakanozban.com/Songs2VID"
 NEXT_PUBLIC_DOCKER_HUB_URL="https://hub.docker.com/r/atakanozban/songs2vid"
-
-# Optional: override the bundled ffmpeg-static binary.
-# FFMPEG_PATH="C:/path/to/ffmpeg.exe"