compose-checklisted

# compose-check Catch a broken compose stack *before* `docker compose up`, not after. Validates syntax, interpolation, and env wiring — strictly **read-only**. This skill never runs `up`, `down`, `pull`, or anything that mutates a stack or shared state. ## When this applies Editing a `docker-compose*.yml` / `compose.ya?ml`, or about to deploy one, or asked to "check / validate the compose stack." Cheap; run it whenever in doubt. ## Check each stack 1. **Find stacks** — `docker-compose.yml`, `docker-compose.*.yml`, `compose.yml`, `compose.yaml` (skip dated backups like `*.yml.<date>`). If none, say so. 2. **Validate structure, then classify** — for each file: ```bash docker compose -f <file> config -q ``` A fresh checkout usually has no `.env` (gitignored, present only on the deploy host), so separate "not ready" from "broken": - **exit 0** → structure + interpolation valid → **PASS** - **fails *only* with `env file ... not found`** → the YAML is fine, the stack just needs an `.env` absent from this checkout → **ENV-MISSING** (warn, name the exact path). Not a defect. - **any other error** (YAML parse, `additional property`, bad interpolation, `required variable is missing`) → **FAIL** — surface the message. 3. **Undefined interpolation** — grep for `${VAR}` used *without* a default or required marker (`${VAR:-default}` / `${VAR:?msg}`). Any bare `${VAR}` not set in the environment or an `.env` becomes an empty string at run