refactor(paseo): install gh, glab, uv and Python into home

Drop them from the image; the README gives the commands to install each
into ~/.local/bin on the home volume. System packages stay in the image.

paseo/Dockerfile

@@ -1,6 +1,5 @@
-# Adds Python, a C toolchain and CLI tooling to the official image, which ships
-# none of it. Agent CLIs are not among them -- see README.md, which carries the
-# reasoning for everything here.
+# Adds a C toolchain, sudo, zsh and nano to the official image. See README.md,
+# which carries the reasoning for everything here.
 FROM ghcr.io/getpaseo/paseo:latest
 
 # --- system packages -------------------------------------------------------
@@ -11,33 +10,8 @@ RUN apt-get update \
  && rm -rf /var/lib/apt/lists/* \
  && usermod -aG sudo paseo
 
-# --- python ----------------------------------------------------------------
-ARG PYTHON_VERSION=3.12
-ENV UV_INSTALL_DIR=/usr/local/bin \
-    UV_PYTHON_INSTALL_DIR=/opt/python \
-    UV_PYTHON_BIN_DIR=/usr/local/bin
-RUN curl -fsSL https://astral.sh/uv/install.sh | sh \
- && uv python install "${PYTHON_VERSION}" --default
-
-# --- gh and glab -----------------------------------------------------------
-# gh from GitHub's signed apt repository, glab from the .deb on its releases
-# page.
-ARG GLAB_VERSION=1.118.0
-RUN install -d -m 0755 /etc/apt/keyrings \
- && curl -fsSL https://cli.github.com/packages/githubcli-archive-keyring.gpg \
-      -o /etc/apt/keyrings/githubcli-archive-keyring.gpg \
- && chmod go+r /etc/apt/keyrings/githubcli-archive-keyring.gpg \
- && echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/githubcli-archive-keyring.gpg] https://cli.github.com/packages stable main" \
-      > /etc/apt/sources.list.d/github-cli.list \
- && curl -fsSL "https://gitlab.com/gitlab-org/cli/-/releases/v${GLAB_VERSION}/downloads/glab_${GLAB_VERSION}_linux_$(dpkg --print-architecture).deb" \
-      -o /tmp/glab.deb \
- && apt-get update \
- && apt-get install -y --no-install-recommends gh /tmp/glab.deb \
- && rm -f /tmp/glab.deb \
- && rm -rf /var/lib/apt/lists/*
-
 # --- agent cli path --------------------------------------------------------
-# Puts the $HOME directories the agent installers write to on PATH.
+# Puts the $HOME directories the agent and tool installers write to on PATH.
 ENV PATH=/home/paseo/.local/bin:/home/paseo/.opencode/bin:$PATH
 
 # --- entrypoint ------------------------------------------------------------