The .app-header__logo SVG was decorative on every tool. Web's
strongest convention is "click logo → go home" — so users tapping
it expecting that fallback got nothing. Now the logo is wrapped in
an anchor whose href reflects the URL the page was loaded from:
file:// → no wrap (no server home to point at)
/ → wrap, href=/ (deployment root)
/index.html / /<tool>.html → wrap, href=/ (root, no project)
/<project>/... → wrap, href=/<project> (project landing)
The wrap happens client-side at DOMContentLoaded via shared/logo.js,
loaded by every tool's build.sh after toast/nav. Idempotent — a
template-supplied anchor or a second mount call is a no-op.
The companion shared/logo.css adds a subtle hover/focus affordance
(opacity 0.82, focus ring) so the logo reads as clickable without
otherwise altering its visual weight. Tools opt out by setting
window.zddc.logo.disabled = true before DOMContentLoaded (e.g. for
deployments that pin the logo to an external destination).
Five Playwright tests (tests/logo.spec.js) lock the contract:
no-wrap on file://, href=/ at root, href=/<project> in project
subtree, aria-label matches target, idempotent re-mount.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>