Move workers from config.yaml to Compose

Migrate this iii project from config.yaml worker declarations to worker-compose.yaml (iii 0.23). Read https://iii.dev/docs/upgrading/workers-to-compose.md first and follow it exactly.

Before changing anything:
1. Locate every config.yaml (including any path passed with --config), any existing worker-compose.yaml, iii.lock, the configuration worker's storage directory (./config by default), and the state, queue, and stream data paths. Copy all of them into ./backup-pre-compose/, preserving each source's relative path so two files with the same name never collide, and stop if a destination already exists. Do not delete the originals.
2. Make sure this project is not already supervised separately (ex. systemd, Kubernetes). If the repository does not make this clear, ask me before writing the file.

Write worker-compose.yaml:
- Move configuration, iii-worker-manager, iii-http-functions, and iii-stream into the engine.workers map. The map value is the worker config itself; drop the old nested config: key. Multiple instances use a #instance suffix.
- Do not declare iii-engine-functions, iii-telemetry, iii-observability, or iii-sandbox. The engine injects them. Read https://iii.dev/docs/upgrading/sandbox-worker for an old iii-sandbox entry.
- Move every other worker under containers:. Rename it per the table on the page (iii-state or state becomes state, iii-http or http becomes http, and so on). Registry workers use package://api.workers.iii.dev/<name> with an explicit version; local workers use path://. Copy each old config: value to config_override and keep every storage path unchanged.
- Translate iii-exec commands into scripts.pre_run, scripts.run, and scripts.post_run.
- Pin versions from iii.lock or the registry. Never invent a version number.
- For a separately supervised engine, keep only the four engine-owned workers in the list-shaped config.yaml, add a top-level sandbox: {adapter, namespace} section if anything calls sandbox::* (without it those calls get S303), and omit engine: from the Compose file.

Stored configuration: for every worker whose configuration id changed (for example iii-state to state), read the old value with configuration::get and raw: true so ${VAR} templates are copied as templates rather than expanded values, put it under config_override or write it to the new id with configuration::set, and verify the new worker before removing the old entry. Do not rename YAML files as a shortcut.

Never edit engine-config.yaml in the Compose state directory. Compose generates it at <project-dir>/.iii/compose/<namespace>/engine-config.yaml by default, or $III_COMPOSE_STATE_DIR/<project-slug>/<namespace>/engine-config.yaml when III_COMPOSE_STATE_DIR is set.

Start the project. iii compose stays in the foreground, so run it in a second terminal or send it to the background with its output in a log file, then wait until it has started every container:
  iii compose --namespace dev --up --file worker-compose.yaml
  (for a separately supervised engine: start the engine with iii --config config.yaml under its own supervisor, then iii compose --namespace dev --engine <that engine's ws:// URL> --up --file worker-compose.yaml)

With the daemon running, show me the output of:
  iii call -n dev compose::status file=worker-compose.yaml
  iii call engine::workers::list
  iii call engine::functions::list
If the engine is not on localhost port 49134, add --address <host> and --port <port> to each iii call command. With an iii CLI older than 0.26, run iii trigger instead of iii call: same arguments (from 0.26, trigger is an alias of call).

If startup reports UNSUPPORTED_CONFIG_WORKERS, UNSUPPORTED_ENGINE_WORKER, ENGINE_WORKER_IS_INJECTED, or any other error from the Common errors list on the page, fix the cause and rerun. Do not work around an error by deleting a worker.

Report back: the resolved path and diff of every configuration file you changed, including any passed with --config, the full new worker-compose.yaml, which stored configuration ids you migrated, and anything you could not migrate.