v1.15.4b: omos-with-pi threshold bump + update-description partial-publish fix

Recovery for v1.15.4's partial publish (omos-with-pi exceeded 3500 MB
smoke threshold; other 3 variants published cleanly). Two changes:

1. omos-with-pi threshold 3500 -> 3700 MB. Compounded growth from
   opencode 1.15.0 -> 1.15.4 (4 patch versions) plus pi 0.74.0 -> 0.75.3
   (minor + 3 patches) summed in the omos-with-pi variant, just over
   the existing limit. Same pattern as prior threshold bumps (v1.14.31c,
   v1.15.0b). Restores ~150 MB headroom for routine apt-upgrade drift.

2. update-description workflow bug fix. Pre-existing latent bug exposed
   by v1.15.4's partial publish: update-description.needs includes all 4
   build-variant-* jobs, and gitea Actions' default behavior is
   'skipped need => skip dependent' \u2014 even when the job's own if:
   condition is satisfied. So when build-variant-omos-with-pi was
   skipped (because its smoke failed), update-description cascaded into
   a skip too, and Hub description didn't refresh on v1.15.4 despite
   3 variants publishing.

   Fix: wrap if: in always() + explicit success check on the base
   variant. Same fix applied to promote-base-latest preemptively (it
   has the same latent bug, currently masked by the cache-hit gate).

No image-side changes \u2014 cache hit on base-35ee5fe7861a.

CHANGELOG.md

@@ -8,6 +8,15 @@ Tags follow `v{opencode_version}[letter]` — bare tag for the first build on a
 
 ## Unreleased
 
+## v1.15.4b — 2026-05-18
+
+Recovery release for v1.15.4 — the `omos-with-pi` variant landed at >3500 MB and tripped the smoke threshold, so `smoke-omos-with-pi` and `build-variant-omos-with-pi` were skipped. The other three variants (base, omos, with-pi) published cleanly. Plus a latent workflow bug fix exposed by the partial publish.
+
+- **Smoke threshold bump:** `omos-with-pi` 3500 → 3700 MB. Compounded growth: opencode 1.15.0 → 1.15.4 (4 patch versions) plus pi 0.74.0 → 0.75.3 (minor + 3 patches) both added a few MB each, and they sum in the omos-with-pi variant. Same pattern as previous threshold bumps (v1.14.31c, v1.15.0b); restores ~150 MB headroom.
+- **Workflow fix — `update-description` no longer skips on partial publish.** Pre-existing latent bug: `update-description.needs` includes all four `build-variant-*` jobs, and gitea Actions' default behavior is "skipped need ⇒ skip dependent". When `build-variant-omos-with-pi` got skipped (because its smoke failed), `update-description` cascaded into a skip even though the job's `if:` condition (`tag pushed`) was true. Result: Hub description wasn't refreshed on v1.15.4 despite three variants publishing. Fix: wrap the `if:` in `always() && needs.build-variant-base.result == 'success' && ...` so the job runs as long as the base variant published, regardless of what other variants did.
+- **Same fix applied to `promote-base-latest`** — had the identical latent bug. Currently masked by the cache-hit skip, but would have surfaced on a real-base-rebuild release with a single failed variant.
+- No image-side changes from v1.15.4. Cache hit on the same base hash (`base-35ee5fe7861a`).
+
 ## v1.15.4 — 2026-05-18
 
 opencode 1.15.3 → 1.15.4 bump (one upstream patch release), bundled with the CI hardening that landed on main between v1.15.3 and now.