feat: add BILIBILI_SESSION_ENCRYPTION_KEY to compose and environment templates

[Aquarius-Situla]

What changed

• Added BILIBILI_SESSION_ENCRYPTION_KEY placeholder to .env.example.
• Exposed BILIBILI_SESSION_ENCRYPTION_KEY: ${BILIBILI_SESSION_ENCRYPTION_KEY:-} under the typetype-server and typetype-init services in docker-compose.yml and docker-compose.dev.yml.

Why the change is needed

In TypeType Beta (1.8.2-beta), BiliBili QR code authentication and session encryption were introduced in TypeType-Server (BiliBiliSessionService). However, the compose stacks and environment template did not pass BILIBILI_SESSION_ENCRYPTION_KEY to the server container, preventing self-hosters from configuring the encryption key for Bilibili sessions out of the box.

Which issue it addresses

Addresses #287 (central stack orchestration part).

How it was tested

• Verified Compose syntax and environment variable expansion on Linux with Docker Compose v2.
• Deployed on a live self-hosted beta instance with a generated encryption key, successfully connecting and encrypting a BiliBili account session in PostgreSQL.

Whether another TypeType component must change with it

No other changes required; TypeType-Server already supports BILIBILI_SESSION_ENCRYPTION_KEY.

[Priveetee]

Hi @Aquarius-Situla ,

I pushed a commit to fix the Compose healthcheck and harden the BiliBili session key setup. The key is now generated automatically during bootstrap instead of leaving the placeholder in place, and the unused typetype-init wiring was removed.

The validate-pr CI job passes and the stack validation is green.

Thanks for contributing to TypeType!