Cosmos servapp: bump pinned image from 0.9.27 to current release

[yusuf-gundogdu]

The Cosmos servapp (azukaar/cosmos-servapps-official#218, tracked in #172) pins
ghcr.io/libredb/libredb-studio to 0.9.27 in
servapps/LibreDB-Studio/cosmos-compose.json. Current release is 0.9.59 —
the servapp is 32 releases behind.

Users installing from the Cosmos Marketplace get a stale build with fixes and
features from 32 releases missing. Needs a version-bump PR against
azukaar/cosmos-servapps-official,
same pattern as the original submission.

[yusuf-gundogdu]

Bump PR opened: azukaar/cosmos-servapps-official#236.

It carries three changes, because preparing the bump surfaced a real bug in the published servapp:

• Login has been broken since the servapp merged (27 June). The template sets JWT_SECRET={Password}, and Cosmos generates 24 characters for that placeholder (randomString(24) in Cosmos-Server), while the app requires at least 32. The container starts and the health endpoint stays green, so the install looks fine, but every login returns 503 "the server's JWT_SECRET is too short". Fixed with {Passwords.0}{Passwords.1} (48 chars).
• Image 0.9.27 to 0.9.59.
• supported_architectures now lists arm64 as well; the image manifest carries both and the tests below ran on aarch64.

Verified locally before submitting, simulating a real Cosmos install: with 24 chars login returns HTTP 503; with 48 chars login returns HTTP 200 (role: admin), a saved connection survives a container restart, and the health endpoint is green throughout.

The visibility side of this (a broken secret looking healthy) is filed separately as #227.