fly.toml's default image tag is several releases behind the latest tag

## What

fly.toml's default image tag is several releases behind the latest tagged release.

## Where

fly.toml:11:

```
image = 'ghcr.io/libredb/libredb-studio:0.14.1'
```

The latest tagged release at the time of filing is `0.15.0`. Product releases are bare semver tags on main, check `git tag | grep -vE '^v|^libredb-studio-' | sort -V | tail -1` for the current one, since more may have shipped by the time this is picked up. docs/FLY.md itself tells users to "bump the image tag in fly.toml to the latest release" when updating an existing deployment, so the template a new user starts from should itself be current.

## Expected

fly.toml's pinned tag matches the latest tagged release on main.

## How to fix

Update the tag in fly.toml:11 to the current latest release tag, using the command above to find it.

## How to check

The tag in fly.toml matches the newest bare semver tag on main.

Open fly.toml at line 11 and use the command in the issue to find the newest bare semver tag on main. Update the pinned image tag, then verify it matches that tag and review docs/FLY.md for the deployment context.

Written by the indexing model from the issue text.