feat: auto-track dev-tools/infra-tools image pins + clear the backlog

Implements docs/development/specs/2026-07-12-image-pins-track-latest-v0.20.2.md.

Adds two Renovate gitlab-tags custom managers so the dev-tools / infra-tools image tags baked into component input defaults (and their reference-doc inputs tables) stay current, and clears the current drift in one pass:

• dev-tools -> v0.3.2: rust-lint/test/security/docs, svelte-build/lint/test/security (go-*/goreleaser were already there).
• infra-tools -> v0.3.1: tofu-* + zensical-pages.

Future image releases flow through the managers as fix(images): bumps, so they cut a release rather than a silent chore(deps):.