Add a new Alpine-based container template for IronClaw. Introduces ct/alpine-ironclaw.sh (installer/launcher with update routine), ct/headers/alpine-ironclaw (ASCII header), install/alpine-ironclaw-install.sh (sets up PostgreSQL 17, pgvector, deploys MUSL prebuilt IronClaw binary, creates OpenRC service and env file), and json/alpine-ironclaw.json (metadata, docs link, ports, resource defaults). The template auto-generates a gateway auth token, uses the MUSL binary for a minimal footprint, and documents post-install steps (ironclaw onboard).
