fix(ci): harden release package publishing (#862)

* fix: pin pnpm for Docker release builds

* test: harden release pnpm version guard

* test: improve release guard diagnostics

* test: cover named pnpm setup steps

* fix: make npm release publishing rerunnable

Dockerfile

@@ -29,7 +29,8 @@ RUN go build -ldflags "-s -w" -o /out/kandev ./cmd/kandev && \
 # ---------------------------------------------------------------------------
 FROM node:24-slim AS web-builder
 
-RUN corepack enable && corepack prepare pnpm@latest --activate
+ARG PNPM_VERSION=9.15.9
+RUN corepack enable && corepack prepare pnpm@${PNPM_VERSION} --activate
 
 WORKDIR /build/apps