feat: add quick install script and packaging (#197)

Give bot-bottle a real distribution path so new users can install
without cloning the repo:

- pyproject.toml: full project metadata, a `bot-bottle` console-script
  entry point (bot_bottle.cli:main), and package-data for the runtime
  assets (Dockerfiles, egress entrypoint, netpool defaults, macos init).
  Still zero runtime pip dependencies.
- install.sh: POSIX, sudo-free, idempotent bootstrapper — checks Python
  >= 3.11, creates ~/.bot-bottle/{agents,bottles,contrib}, installs via
  pipx (pip --user fallback), then runs `bot-bottle doctor`.
- `bot-bottle doctor`: new store-free subcommand reporting Python
  version, backend availability (reuses is_backend_available rather than
  hardcoding Docker), and config-dir presence. Exits non-zero when a hard
  prerequisite is unmet.
- PRD prd-new-install-script and unit tests for doctor, the packaging
  contract, and the install script.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

install.sh

@@ -0,0 +1,79 @@
+#!/bin/sh
+# bot-bottle quick installer.
+#
+# Usage:
+#   curl -fsSL https://gitea.dideric.is/didericis/bot-bottle/raw/branch/main/install.sh | sh
+#
+# Python-native users can skip this entirely:
+#   pipx install bot-bottle        # from a checkout or a published index
+#   uv tool install bot-bottle
+#
+# This script is a thin bootstrapper: it checks prerequisites, installs the
+# package with pipx (falling back to pip --user), creates the config dir, and
+# runs `bot-bottle doctor`. It is idempotent (safe to re-run) and never uses
+# sudo. It does NOT install Docker or a VM backend for you — `doctor` reports
+# what's missing after install.
+set -eu
+
+PACKAGE_SPEC="${BOT_BOTTLE_INSTALL_SPEC:-git+https://gitea.dideric.is/didericis/bot-bottle.git}"
+MIN_PYTHON_MAJOR=3
+MIN_PYTHON_MINOR=11
+
+say() {
+    printf 'bot-bottle install: %s\n' "$*" >&2
+}
+
+die() {
+    say "error: $*"
+    exit 1
+}
+
+# --- prerequisites -----------------------------------------------------------
+
+command -v python3 >/dev/null 2>&1 \
+    || die "python3 ${MIN_PYTHON_MAJOR}.${MIN_PYTHON_MINOR}+ is required but was not found"
+
+python3 - "$MIN_PYTHON_MAJOR" "$MIN_PYTHON_MINOR" <<'PY' || die "python3 ${MIN_PYTHON_MAJOR}.${MIN_PYTHON_MINOR} or newer is required"
+import sys
+
+want = (int(sys.argv[1]), int(sys.argv[2]))
+raise SystemExit(0 if sys.version_info[:2] >= want else 1)
+PY
+
+# --- config directories ------------------------------------------------------
+
+mkdir -p \
+    "${HOME}/.bot-bottle/agents" \
+    "${HOME}/.bot-bottle/bottles" \
+    "${HOME}/.bot-bottle/contrib"
+
+# --- install -----------------------------------------------------------------
+
+if command -v pipx >/dev/null 2>&1; then
+    say "installing with pipx"
+    pipx install --force "${PACKAGE_SPEC}"
+else
+    say "pipx not found; installing with 'python3 -m pip install --user'"
+    python3 -m pip install --user --upgrade "${PACKAGE_SPEC}"
+fi
+
+# --- locate the entry point --------------------------------------------------
+
+if command -v bot-bottle >/dev/null 2>&1; then
+    BOT_BOTTLE_BIN="bot-bottle"
+elif [ -x "${HOME}/.local/bin/bot-bottle" ]; then
+    BOT_BOTTLE_BIN="${HOME}/.local/bin/bot-bottle"
+    say "note: add ${HOME}/.local/bin to your PATH to run 'bot-bottle' directly"
+else
+    die "bot-bottle was installed but is not on PATH; add ~/.local/bin to PATH and re-run"
+fi
+
+# --- verify ------------------------------------------------------------------
+
+say "running '${BOT_BOTTLE_BIN} doctor'"
+if "${BOT_BOTTLE_BIN}" doctor; then
+    say "done. Run '${BOT_BOTTLE_BIN} --help' to get started."
+else
+    say "install completed, but 'doctor' reported unmet prerequisites (see above)."
+    say "resolve them, then re-run '${BOT_BOTTLE_BIN} doctor'."
+fi