Dialog that captures a Supabase access token and runs the provisioning
flow via SupabaseProvisioner. The token lives in a TextEditingController
that is disposed when the dialog closes — it never escapes this widget.
Default implementation: read assets/functions/<slug>.files.txt
(a newline-separated manifest emitted by ./dto schema bundle), then
load each listed file from assets/functions/<slug>/<relative>.
Loader for a bundled Edge Function's source files. Returns the entrypoint
path (e.g. index.ts) plus every file the Management API should receive
in the multipart upload, keyed by relative path. Injectable for tests.