refactor(agent-images): use explicit Debian base

bot_bottle/contrib/claude/Dockerfile

@@ -8,15 +8,15 @@
 # Layer ordering is deliberate: the npm install lives in its own layer so
 # changes to the rest of the repo (or to the CMD) don't bust it.
 
-# Current Node LTS; slim variant keeps the image small while still
-# providing apt-get for any future additions.
-FROM node:22-trixie-slim
+# Debian stable is the supported userspace. The provider's Node.js runtime is
+# installed explicitly below rather than inherited from a language image.
+FROM debian:trixie-slim
 
 # Install runtime system deps. claude-code shells out to git for several
 # features (status checks, commits, PR creation) — without git in the
 # image, those features fail in surprising ways once the user does any
-# real work. ca-certificates is already in the slim base; listed for
-# clarity in case the base ever drops it. curl is here so any
+# real work. ca-certificates is installed explicitly for TLS clients. curl is
+# here so any
 # HTTPS_PROXY-aware tool (curl itself, plus anything that shells out
 # to it) works against egress's bumped TLS without the agent needing
 # local DNS.
@@ -30,8 +30,13 @@ RUN apt-get update \
   ripgrep \
   iproute2 \
   dnsutils \
+  nodejs \
+  npm \
   && rm -rf /var/lib/apt/lists/*
 
+RUN groupadd --gid 1000 node \
+  && useradd --uid 1000 --gid node --shell /bin/bash --create-home node
+
 # App-specific deps. Python isn't required by claude-code itself
 # (claude-code is a Node CLI), but is convenient for the agent to
 # shell out to for ad-hoc scripts. Kept on its own layer so it can
@@ -52,9 +57,8 @@ RUN npm install -g --no-fund --no-audit @anthropic-ai/claude-code@2.1.172 \
 # suppress bot-bottle's git-gate insteadOf rules.
 RUN install -d -o node -g node -m 755 /home/node/.config /home/node/.config/git
 
-# Run as a non-root user. The node image already provides a `node` user
-# (uid 1000) with a home directory, which is where claude-code will write
-# its session state.
+# Run as the explicitly-created non-root user. Claude Code writes its session
+# state under this user's home directory.
 USER node
 WORKDIR /home/node