## What
`ci/main.go` previously hardcoded the Flutter container image tag (`ghcr.io/cirruslabs/flutter:3.44.0`) separately from `.fvmrc` (`{ "flutter": "3.44.1" }`). These two values drifted, causing the deploy failure in #394.
## How
`New()` now accepts `ctx context.Context` and returns `(*Ci, error)`. It reads `.fvmrc` from the source directory, parses the `flutter` field, and stores it as `Ci.FlutterVersion`. `toolchain()` constructs the image tag as `"ghcr.io/cirruslabs/flutter:" + m.FlutterVersion`. `Graph()` also uses the live value instead of a stale literal.
Result: `.fvmrc` is the single source of truth. Bumping Flutter via Renovate or manually only requires editing `.fvmrc`; the Dagger pipeline picks up the new version automatically.
## Verification
- `gofmt -e ci/main.go` passes
- No schema changes; no `build_runner` run needed
Closes #396
Co-authored-by: Thomas SharedInbox <sharedinbox@thomas-guettler.de>
Co-authored-by: guettli <guettli@noreply.codeberg.org>
Reviewed-on: https://codeberg.org/guettli/sharedinbox/pulls/405