fix: make installed wheel self-contained + harden install.sh prereqs

Addresses the review on PR #481.

Self-contained wheel (review point 1): the gateway/infra/orchestrator
images build from a context that must hold bot_bottle/, pyproject.toml,
and the root-level Dockerfiles. Modules previously located these by
walking __file__ to the repo root, so an installed wheel (package in
site-packages, no repo root) passed `doctor` but failed `start`.

- Add bot_bottle/resources.py: build_root() returns the repo root in a
  checkout (unchanged) or a staged copy from the wheel's bundled
  _resources/ otherwise; dockerfile()/nix_netpool_module()/
  netpool_script() derive from it.
- setup.py bundles the root Dockerfiles, nix module, netpool script, and
  pyproject.toml into bot_bottle/_resources/ at build; MANIFEST.in ships
  them in the sdist.
- Route every _REPO_ROOT/_REPO_DIR call site (docker/macos launch, macos
  infra, firecracker infra_vm/infra_artifact/setup, orchestrator
  lifecycle/gateway) through resources. Checkout behavior is unchanged.

install.sh prerequisites (review point 2): check for git when installing
a git+ spec, and — before the pip fallback — that pip is usable and the
interpreter isn't externally managed (PEP 668), pointing at pipx.

Tests: test_resources covers checkout + staged-wheel layouts;
test_wheel_install builds the wheel, installs it into an isolated venv,
and asserts `doctor` runs and build_root() yields a valid context.
Running `start` end-to-end still needs a Docker/KVM host (CI).

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

tests/unit/test_wheel_install.py

@@ -0,0 +1,119 @@
+"""Integration: build the wheel, install it into an isolated venv, and prove
+the installed distribution is self-contained.
+
+This is the boundary a source-tree existence test can't reach (issue #197
+review): under an installed wheel the package lives in ``site-packages`` with
+no repo root above it, so anything resolving Dockerfiles / nix / scripts from
+``__file__``'s parents would break. Here we install for real and assert that
+``bot-bottle doctor`` runs from the console script and that
+``bot_bottle.resources`` stages a valid, repo-root-shaped build context.
+
+It does NOT run `start` — building images needs a Docker/KVM host (CI). It
+skips cleanly when the build/venv toolchain isn't available.
+"""
+
+from __future__ import annotations
+
+import subprocess
+import sys
+import tempfile
+import unittest
+from pathlib import Path
+
+REPO_ROOT = Path(__file__).resolve().parents[2]
+
+
+class TestWheelInstall(unittest.TestCase):
+    """`build` is a declared dev dependency (requirements-dev.txt), so this runs
+    in CI. A build/install failure is a real packaging regression and FAILS —
+    only genuinely-unsupported infra (no `venv`/`ensurepip`) skips."""
+
+    _tmp: "tempfile.TemporaryDirectory[str]"
+    venv_py: Path
+    app_root: Path
+
+    @classmethod
+    def setUpClass(cls):
+        cls._tmp = tempfile.TemporaryDirectory(  # pylint: disable=consider-using-with
+            prefix="bb-wheel-")
+        tmp = Path(cls._tmp.name)
+        dist = tmp / "dist"
+
+        # A failed wheel build is exactly the regression this test guards — fail,
+        # don't skip. `build` is installed via requirements-dev.txt.
+        built = subprocess.run(
+            [sys.executable, "-m", "build", "--wheel", "--outdir", str(dist), str(REPO_ROOT)],
+            capture_output=True, text=True, check=False,
+        )
+        if built.returncode != 0:
+            raise AssertionError(f"wheel build failed:\n{built.stderr[-2000:]}")
+        wheels = list(dist.glob("*.whl"))
+        if not wheels:
+            raise AssertionError(f"no wheel produced:\n{built.stdout[-2000:]}")
+
+        # A missing `venv`/`ensurepip` is unsupported optional infra, not a
+        # packaging bug — skip only here.
+        venv = tmp / "venv"
+        made = subprocess.run([sys.executable, "-m", "venv", str(venv)],
+                              capture_output=True, text=True, check=False)
+        if made.returncode != 0:
+            raise unittest.SkipTest(f"venv/ensurepip unavailable:\n{made.stderr[-1500:]}")
+        cls.venv_py = venv / "bin" / "python"
+
+        # Installing the freshly-built wheel must succeed — fail if it doesn't.
+        install = subprocess.run(
+            [str(cls.venv_py), "-m", "pip", "install", "--quiet", str(wheels[0])],
+            capture_output=True, text=True, check=False,
+        )
+        if install.returncode != 0:
+            raise AssertionError(f"pip install of the wheel failed:\n{install.stderr[-2000:]}")
+
+        # Isolate the staged build root the wheel writes under the app-data dir.
+        cls.app_root = tmp / "appdata"
+
+    @classmethod
+    def tearDownClass(cls):
+        cls._tmp.cleanup()
+
+    def _run(self, tail: "list[str]") -> "subprocess.CompletedProcess[str]":
+        """Run the installed venv's python with `tail` appended, from a neutral
+        cwd so the source checkout isn't on sys.path — we must import the
+        *installed* package, not the repo we built from."""
+        env = {"BOT_BOTTLE_ROOT": str(self.app_root), "PATH": "/usr/bin:/bin"}
+        return subprocess.run(
+            [str(self.venv_py), *tail],
+            capture_output=True, text=True, env=env, cwd=self._tmp.name, check=False,
+        )
+
+    def test_console_entry_point_installed(self):
+        # The `bot-bottle` script the wheel declares must exist in the venv.
+        script = self.venv_py.parent / "bot-bottle"
+        self.assertTrue(script.is_file(), "bot-bottle console script not installed")
+
+    def test_doctor_runs_from_installed_package(self):
+        proc = self._run(["-m", "bot_bottle.cli", "doctor"])
+        # doctor exits non-zero here (no backend), but it must RUN and report.
+        self.assertIn("python", proc.stdout)
+        self.assertIn(proc.returncode, (0, 1))
+
+    def test_installed_wheel_is_self_contained(self):
+        # From the installed layout (not a checkout), resources must resolve
+        # Dockerfiles and stage a repo-root-shaped build context.
+        script = (
+            "import bot_bottle.resources as r\n"
+            "assert not r.is_source_checkout(), 'should not look like a checkout'\n"
+            "assert r.dockerfile('Dockerfile.gateway').is_file()\n"
+            "assert r.nix_netpool_module().is_file()\n"
+            "assert r.netpool_script().is_file()\n"
+            "root = r.build_root()\n"
+            "assert (root / 'bot_bottle' / '__init__.py').is_file(), 'no package in context'\n"
+            "assert (root / 'pyproject.toml').is_file(), 'no pyproject in context'\n"
+            "assert (root / 'Dockerfile.gateway').is_file(), 'no Dockerfile in context'\n"
+            "print('SELF_CONTAINED_OK')\n"
+        )
+        proc = self._run(["-c", script])
+        self.assertIn("SELF_CONTAINED_OK", proc.stdout, msg=proc.stderr)
+
+
+if __name__ == "__main__":
+    unittest.main()