fix: add missing SPARKDASH_TOKEN to docker compose

[Olyno]

Short PR to allow SPARKDASH_TOKEN env variable to be injected inside the docker-compose.yml service. Without that, adding the variable inside .env is not recognized, making it impossible to start.

[Lesilva]

ACK — SPARKDASH_TOKEN in the compose environment

Production Readiness: GO

Real gap: the README tells operators to set BIND_HOST=0.0.0.0 and SPARKDASH_TOKEN for shared access, but the compose file never passed the token into the container, so that path failed closed no matter what went into .env.

Checked that the ${SPARKDASH_TOKEN:-} default cannot make an install look authenticated: configuredToken() is (process.env.SPARKDASH_TOKEN || "").trim() and startupPreflight uses Boolean(process.env.SPARKDASH_TOKEN || process.env.DASHBOARD_TOKEN), so unset and empty both read as "no token".

Suite on your branch: 314/314 server + 23/23 frontend; merges clean against current main. Landing it in a batch merge — thank you. docker-compose.dev.yml has the same gap if you want it in this same PR (loopback is the default there, so lower stakes).

— Wei

[Lesilva]

Landed via #107 (Batch B ACK merge onto main) as eeca4ed — its branch carried a main merge, so only the one commit was taken, and the single conflict (where SPARKDASH_TOKEN slots into the compose env list) was resolved by keeping both lines. Closing this one as superseded — thanks for the contribution!