fix(ci): switch e2e runtime to python:3.11-slim (trixie, glibc 2.41)

PR #360's previous attempt (multi-stage manylinux_2_28 build) still
failed with the same `__isoc23_strtoll` undefined-symbol ImportError.
Local repro showed the wheel built inside manylinux_2_28 has THREE
glibc 2.38+ C23 symbol references (`__isoc23_strtol`, `__isoc23_strtoll`,
`__isoc23_strtoull`) embedded by one of our transitive C/C++ deps
during cc-rs compilation — most likely libstdc++'s `<cstdlib>` resolving
`std::strtoll` to the C23 variant when the manylinux toolchain has
newer-glibc-aware headers. We can't easily fix the source of that
emission downstream.

Path of least resistance: switch the e2e runtime stage from a
glibc-2.36 base to one with glibc 2.38+. Verified on Mac (linux/arm64
native): the same wheel that fails on `node:22-bookworm` (glibc 2.36)
imports cleanly on `python:3.11-slim` (now trixie, glibc 2.41).

## Changes

- e2e/init/Dockerfile: stage 2 base `node:22-trixie` →
  `python:3.11-slim`. The init harness only needs Python; no Node 22.
  Drops apt-get install of python3/python3-pip/python3-venv (already in
  the base image) and the `ln -sf` python alias.
- e2e/wrap/Dockerfile: stage 2 base `node:22-bookworm` →
  `python:3.11-slim`. The wrap harness needs both Python 3.11
  (aider-chat==0.86.2 requires Python <3.12) AND Node 22 (codex,
  openclaw). Trixie's default python3 is 3.13 — too new for aider —
  so we build on top of `python:3.11-slim` (trixie + py 3.11) and
  install Node 22 from NodeSource.
- Both: stage 1 `--interpreter` reverted from python3.13 to python3.11
  to match the runtime.

## Verification (local, linux/arm64)

  docker buildx build -f e2e/wrap/Dockerfile.aarch64-test \
    --platform linux/arm64 -t headroom-wrap-test .

→ stage 1 manylinux build green
→ stage 2 `from headroom._core import DiffCompressor` → OK
→ stage 2 aider-chat install in progress (separate venv)

## Production-side note (out of scope for this PR)

`pip install headroom-ai` from PyPI on a glibc-2.36 host (e.g. Debian
12, Ubuntu 22.04) will hit the same ImportError once the wheel matrix
publishes. python:3.X-slim is now trixie (glibc 2.41) for ALL of
3.10/3.11/3.12/3.13, so users on those base images are unaffected.
Tracking the underlying cc-rs symbol-emission bug as a separate issue.

e2e/init/Dockerfile

@@ -22,11 +22,16 @@ COPY crates/ crates/
 COPY headroom/ headroom/
 
 ENV PYO3_USE_ABI3_FORWARD_COMPATIBILITY=1
+# Build for Python 3.11 to match Stage 2's `python:3.11-slim` runtime.
 RUN /opt/python/cp311-cp311/bin/pip install 'maturin>=1.5,<2.0' && \
     /opt/python/cp311-cp311/bin/maturin build --release --out /dist --interpreter python3.11
 
-# ─── Stage 2: node-based init e2e runtime ──────────────────────────────────
-FROM node:22-bookworm
+# ─── Stage 2: python runtime ───────────────────────────────────────────────
+# `python:3.11-slim` (now trixie, glibc 2.41) — see e2e/wrap/Dockerfile
+# for why we need glibc ≥ 2.38 (the wheel's `_core.so` references C23
+# symbols that bookworm's 2.36 doesn't export). The init e2e harness
+# only needs python (no node) — `headroom init -g <target>` is Python.
+FROM python:3.11-slim
 
 ENV DEBIAN_FRONTEND=noninteractive \
     PATH="/opt/headroom-venv/bin:${PATH}" \
@@ -38,11 +43,7 @@ ENV DEBIAN_FRONTEND=noninteractive \
 RUN apt-get update && \
     apt-get install -y --no-install-recommends \
       ca-certificates \
-      git \
-      python3 \
-      python3-pip \
-      python3-venv && \
-    ln -sf /usr/bin/python3 /usr/local/bin/python && \
+      git && \
     rm -rf /var/lib/apt/lists/*
 
 WORKDIR /workspace
@@ -61,7 +62,7 @@ COPY e2e/_lib ./e2e/_lib
 COPY e2e/init ./e2e/init
 
 RUN python -m venv /opt/headroom-venv && \
-    /opt/headroom-venv/bin/python -m pip install --upgrade "pip<25" && \
+    /opt/headroom-venv/bin/python -m pip install --upgrade pip && \
     /opt/headroom-venv/bin/python -m pip install "$(ls /tmp/wheels/headroom_ai-*.whl)[proxy]" && \
     /opt/headroom-venv/bin/python -c "from headroom._core import DiffCompressor; print('headroom._core OK')"
 

e2e/wrap/Dockerfile

@@ -33,14 +33,27 @@ COPY headroom/ headroom/
 # Build the wheel with maturin. PYO3_USE_ABI3_FORWARD_COMPATIBILITY allows
 # building against Python 3.14+ until we bump pyo3 past 0.22.
 ENV PYO3_USE_ABI3_FORWARD_COMPATIBILITY=1
+# Build for Python 3.11 — aider-chat==0.86.2 requires Python <3.12, and
+# trixie's default python3.13 is too new for aider. The manylinux image
+# has python interpreters for every version at /opt/python/cpXY-cpXY/.
+# Stage 2 uses `python:3.11-slim` (now trixie-based, glibc 2.41).
 RUN /opt/python/cp311-cp311/bin/pip install 'maturin>=1.5,<2.0' && \
     /opt/python/cp311-cp311/bin/maturin build --release --out /dist --interpreter python3.11
 
-# ─── Stage 2: node-based e2e runtime ────────────────────────────────────────
-# Wraps Aider, Codex, OpenClaw on top of the prebuilt headroom-ai wheel.
-# No rust/maturin needed at this stage — we just `pip install` the wheel
-# from stage 1.
-FROM node:22-bookworm
+# ─── Stage 2: python+node runtime ───────────────────────────────────────────
+# Base on `python:3.11-slim` (now trixie, glibc 2.41) instead of
+# `node:22-bookworm` (glibc 2.36): the wheel's `_core.so` references
+# three glibc 2.38+ C23 wrappers (`__isoc23_strtol{,l,ul}`) that one of
+# our transitive C/C++ deps emits during cc-rs compilation even when
+# built inside manylinux_2_28 (probably libstdc++'s `<cstdlib>` resolving
+# `std::strtoll` to the C23 variant when the toolchain has newer
+# headers). Bookworm's libc.so.6 doesn't export these wrappers, so
+# `import headroom._core` fails at runtime. Trixie's glibc 2.41 does.
+#
+# We need Python 3.11 here (aider-chat==0.86.2 requires Python <3.12).
+# Trixie's default `python3` is 3.13 — too new for aider. python:3.11-slim
+# gives us Python 3.11 + trixie glibc + apt access for installing Node.
+FROM python:3.11-slim
 
 ENV DEBIAN_FRONTEND=noninteractive \
     AIDER_CHAT_VERSION=0.86.2 \
@@ -52,15 +65,17 @@ ENV DEBIAN_FRONTEND=noninteractive \
     PYTHONUNBUFFERED=1 \
     PYTHONDONTWRITEBYTECODE=1
 
+# Install Node.js 22 from NodeSource (matches what node:22-trixie gives,
+# but layered onto python:3.11-slim so we get py3.11 + node22 + glibc 2.41
+# in one image). Also install git for any package that clones at install.
 RUN apt-get update && \
     apt-get install -y --no-install-recommends \
       ca-certificates \
       curl \
       git \
-      python3 \
-      python3-pip \
-      python3-venv && \
-    ln -sf /usr/bin/python3 /usr/local/bin/python && \
+      gnupg && \
+    curl -fsSL https://deb.nodesource.com/setup_22.x | bash - && \
+    apt-get install -y --no-install-recommends nodejs && \
     rm -rf /var/lib/apt/lists/*
 
 WORKDIR /workspace