build-release.sh: two steps still succeed after doing nothing — an unresolved Ghostty share tree and a failed asset compile

[fairchild]

Follow-up to #1502 / PR #1591, which made the two resource copies fail-closed. Two neighbouring steps in scripts/build-release.sh keep the old shape: they log and continue after producing nothing, so the build exits 0 and the gap is only visible downstream.

Where

1. scripts/build-release.sh:566-568 — when resolve_ghostty_share_dir fails, the else-arm logs Ghostty share resources not found; packaged shell integration may be degraded and the build goes on. A bundle with no Ghostty resources (no shell integration, no terminfo/78/xterm-ghostty) is produced with exit 0. Today verify-release-bundle.sh --structure-only (run by ci.yml on the next step, and by the release lane) catches it as Missing Ghostty resources directory, so the consequence is a false-green build step rather than a shipped bundle. Codex rated it Medium on fix(release): resource copies into the bundle fail the build instead of logging success #1591; declined there on the fence.
2. scripts/build-release.sh:576-581 — actool … 2>/dev/null || log_warning "Asset compilation had warnings". A failed compile leaves an app without Assets.car, logged as a warning. verify-release-bundle.sh does not assert Assets.car, so nothing downstream catches an iconless bundle.

What to decide

• Whether an unresolved Ghostty share tree is ever a legitimate local state (a dev build without the Ghostty build cache) or always a broken release build. If the former, the flag that opts into a degraded bundle should be explicit, not the default.
• Which actool warnings this build emits routinely, so that turning the step fail-closed does not break the release lane on noise. fix(release): resource copies into the bundle fail the build instead of logging success #1591 deliberately left this alone for lack of that baseline; capture one from a --no-sign build before changing the step.

Requested Evidence

• A test in scripts/tests/test_build_release_copies.py (or a sibling) asserting the chosen behaviour for each step, red before the change
• ./scripts/build-release.sh --no-sign end to end followed by ./scripts/verify-release-bundle.sh --structure-only build/WorkSpaces.app, both result lines quoted
• uv run --script scripts/validate-release-changes.py passes for the changed files

Orchestrator note (workspaces)