fix(ci): use Kaniko for base image build (no privileged mode needed)

apps/api/Dockerfile

@@ -1,7 +1,7 @@
 # Base image for all stages
 # Uses Debian slim (glibc) instead of Alpine (musl) because native Node.js addons
 # (matrix-sdk-crypto-nodejs, Prisma engines) require glibc-compatible binaries.
-FROM git.mosaicstack.dev/mosaic/node-base:24-slim AS base
+FROM node:24-slim AS base
 
 # Install pnpm globally
 RUN corepack enable && corepack prepare pnpm@10.27.0 --activate
@@ -19,9 +19,9 @@ COPY turbo.json ./
 FROM base AS deps
 
 # Install build tools for native addons (node-pty requires node-gyp compilation)
-# Note: openssl and ca-certificates pre-installed in base image
+# and OpenSSL for Prisma engine detection
 RUN apt-get update && apt-get install -y --no-install-recommends \
-    python3 make g++ \
+    python3 make g++ openssl \
     && rm -rf /var/lib/apt/lists/*
 
 # Copy all package.json files for workspace resolution
@@ -61,14 +61,19 @@ RUN pnpm turbo build --filter=@mosaic/api --force
 # ======================
 # Production stage
 # ======================
-FROM git.mosaicstack.dev/mosaic/node-base:24-slim AS production
+FROM node:24-slim AS production
 
-# dumb-init, openssl, ca-certificates pre-installed in base image
+# Install dumb-init for proper signal handling (static binary from GitHub,
+# avoids apt-get which fails under Kaniko with bookworm GPG signature errors)
+ADD https://github.com/Yelp/dumb-init/releases/download/v1.2.5/dumb-init_1.2.5_x86_64 /usr/local/bin/dumb-init
 
 # Single RUN to minimize Kaniko filesystem snapshots (each RUN = full snapshot)
-# - Remove npm/npx to reduce image size (not used in production)
-# - Create non-root user
-RUN rm -rf /usr/local/lib/node_modules/npm /usr/local/bin/npm /usr/local/bin/npx \
+# - openssl: Prisma engine detection requires libssl
+# - No build tools needed here — native addons are compiled in the deps stage
+RUN apt-get update && apt-get install -y --no-install-recommends openssl \
+    && rm -rf /var/lib/apt/lists/* \
+    && rm -rf /usr/local/lib/node_modules/npm /usr/local/bin/npm /usr/local/bin/npx \
+    && chmod 755 /usr/local/bin/dumb-init \
     && groupadd -g 1001 nodejs && useradd -m -u 1001 -g nodejs nestjs
 
 WORKDIR /app

apps/orchestrator/Dockerfile

@@ -1,6 +1,6 @@
 # Base image for all stages
 # Uses Debian slim (glibc) instead of Alpine (musl) for native addon compatibility.
-FROM git.mosaicstack.dev/mosaic/node-base:24-slim AS base
+FROM node:24-slim AS base
 
 # Install pnpm globally
 RUN corepack enable && corepack prepare pnpm@10.27.0 --activate
@@ -54,7 +54,7 @@ RUN find ./apps/orchestrator/dist \( -name '*.spec.js' -o -name '*.spec.js.map'
 # ======================
 # Production stage
 # ======================
-FROM git.mosaicstack.dev/mosaic/node-base:24-slim AS production
+FROM node:24-slim AS production
 
 # Add metadata labels
 LABEL maintainer="mosaic-team@mosaicstack.dev"
@@ -65,12 +65,13 @@ LABEL org.opencontainers.image.vendor="Mosaic Stack"
 LABEL org.opencontainers.image.title="Mosaic Orchestrator"
 LABEL org.opencontainers.image.description="Agent orchestration service for Mosaic Stack"
 
-# dumb-init, ca-certificates pre-installed in base image
+# Install dumb-init for proper signal handling (static binary from GitHub,
+# avoids apt-get which fails under Kaniko with bookworm GPG signature errors)
+ADD https://github.com/Yelp/dumb-init/releases/download/v1.2.5/dumb-init_1.2.5_x86_64 /usr/local/bin/dumb-init
 
 # Single RUN to minimize Kaniko filesystem snapshots (each RUN = full snapshot)
-# - Remove npm/npx to reduce image size (not used in production)
-# - Create non-root user
 RUN rm -rf /usr/local/lib/node_modules/npm /usr/local/bin/npm /usr/local/bin/npx \
+    && chmod 755 /usr/local/bin/dumb-init \
     && groupadd -g 1001 nodejs && useradd -m -u 1001 -g nodejs nestjs
 
 WORKDIR /app

apps/web/Dockerfile

@@ -1,7 +1,7 @@
 # Base image for all stages
 # Uses Debian slim (glibc) for consistency with API/orchestrator and to prevent
 # future native addon compatibility issues with Alpine's musl libc.
-FROM git.mosaicstack.dev/mosaic/node-base:24-slim AS base
+FROM node:24-slim AS base
 
 # Install pnpm globally
 RUN corepack enable && corepack prepare pnpm@10.27.0 --activate
@@ -87,14 +87,15 @@ RUN mkdir -p ./apps/web/public
 # ======================
 # Production stage
 # ======================
-FROM git.mosaicstack.dev/mosaic/node-base:24-slim AS production
+FROM node:24-slim AS production
 
-# dumb-init, ca-certificates pre-installed in base image
+# Install dumb-init for proper signal handling (static binary from GitHub,
+# avoids apt-get which fails under Kaniko with bookworm GPG signature errors)
+ADD https://github.com/Yelp/dumb-init/releases/download/v1.2.5/dumb-init_1.2.5_x86_64 /usr/local/bin/dumb-init
 
 # Single RUN to minimize Kaniko filesystem snapshots (each RUN = full snapshot)
-# - Remove npm/npx to reduce image size (not used in production)
-# - Create non-root user
 RUN rm -rf /usr/local/lib/node_modules/npm /usr/local/bin/npm /usr/local/bin/npx \
+    && chmod 755 /usr/local/bin/dumb-init \
     && groupadd -g 1001 nodejs && useradd -m -u 1001 -g nodejs nextjs
 
 WORKDIR /app

docker/base.Dockerfile

@@ -1,16 +0,0 @@
-FROM node:24-slim AS base
-
-# Pre-bake OS updates and common packages shared across all apps.
-# Rebuild this image weekly or when base packages change.
-# Push to: git.mosaicstack.dev/mosaic/node-base:24-slim
-RUN apt-get update && apt-get upgrade -y --no-install-recommends \
-    && apt-get install -y --no-install-recommends \
-        openssl \
-        ca-certificates \
-        curl \
-        dumb-init \
-    && apt-get clean \
-    && rm -rf /var/lib/apt/lists/*
-
-# Enable corepack for pnpm
-RUN corepack enable