gcp-spend-cap-setuplisted

# GCP Spend-Cap Setup (GUIDED) ## Overview Google's [spend caps on budgets](https://docs.cloud.google.com/billing/docs/how-to/budgets-spend-caps) (Public Preview since 2026-07-29) actually pause a service when a monthly threshold is hit — but creation is **console-only**: the Billing Budget API v1 has no enforcement field and `gcloud billing budgets create` has no cap flag. This skill is therefore **GUIDED**: it runs only read-only commands itself; you perform the single mutation in the console; the skill prepares everything before and verifies everything after. A tripped cap returns permission errors (403) to ALL callers of that service, including production. Choosing to cap is a human decision — that is by design. ## When to Use - Standalone, whenever you want hard caps on AI/serverless spend. - After a `gcp-ironclad` run: the final report's `recommend_spend_cap` flags point here. - **During an active incident.** Unlike the APPLY skills, there is no bleeding-halt gate — a spend cap is precisely the emergency brake, so this skill must work while a project is bleeding. ## Inputs - `SESSION_DIR` env var — session directory; create `/tmp/gcp-ironclad/<iso-ts>/` if unset (same convention as the other skills). - `MODE` env var — unset for a full run; `verify` to skip to Step 4 using a prior `${SESSION_DIR}/spend-caps.json`. - No `DRY_RUN`: the skill never mutates, so there is nothing to dry-run. ## Outputs - `${SESSION_DIR}/spend-caps.json` — matches `output.schema.json`