refactor: convert project from bash to Python

Replaces cli.sh + lib/*.sh with a claude_bottle/ Python package and a
cli.py entry point. No external dependencies — uses only Python's
stdlib (json, subprocess, getpass, tempfile, argparse, re, etc.).

- claude_bottle/{log,docker,manifest,env_resolve,network,pipelock,
  skills,ssh,cli}.py mirror the previous lib/*.sh modules.
- Tests converted to unittest under tests/test_*.py with a stdlib
  runner at tests/run_tests.py (unit | integration | path).
- .githooks/commit-msg ported to Python; same Conventional Commits rules.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

claude_bottle/skills.py

@@ -0,0 +1,76 @@
+"""Skill copier: host's ~/.claude/skills/<name>/ -> container's
+~/.claude/skills/<name>/, preserving directory structure."""
+
+from __future__ import annotations
+
+import os
+import subprocess
+
+from .log import die, info
+
+CONTAINER_HOME = os.environ.get("CLAUDE_BOTTLE_CONTAINER_HOME", "/home/node")
+CONTAINER_SKILLS_DIR = os.environ.get(
+    "CLAUDE_BOTTLE_CONTAINER_SKILLS_DIR", f"{CONTAINER_HOME}/.claude/skills"
+)
+
+
+def host_skill_dir(name: str) -> str:
+    home = os.environ.get("HOME")
+    if not home:
+        die("HOME not set")
+    return f"{home}/.claude/skills/{name}"
+
+
+def host_skill_exists(name: str) -> bool:
+    return os.path.isdir(host_skill_dir(name))
+
+
+def require_host_skill(name: str) -> None:
+    if not host_skill_exists(name):
+        die(
+            f"skill '{name}' not found on host at {host_skill_dir(name)}. "
+            f"Create it under ~/.claude/skills/, then re-run."
+        )
+
+
+def skills_validate_all(names: list[str]) -> None:
+    """Use BEFORE the y/N so the user does not get asked about a plan
+    that's already known to fail."""
+    for n in names:
+        require_host_skill(n)
+
+
+def skills_copy_into(container: str, names: list[str]) -> None:
+    """For each named skill, ensure the parent dir exists, wipe any
+    prior copy, then `docker cp <host>/. <container>:<dst>/` so the
+    contents are copied into a freshly-created destination dir."""
+    if not names:
+        return
+
+    subprocess.run(
+        ["docker", "exec", container, "mkdir", "-p", CONTAINER_SKILLS_DIR],
+        stdout=subprocess.DEVNULL,
+        check=True,
+    )
+
+    for n in names:
+        src = host_skill_dir(n)
+        if not os.path.isdir(src):
+            die(f"skill '{n}' disappeared from host between validation and copy at {src}.")
+        dst = f"{CONTAINER_SKILLS_DIR}/{n}"
+        info(f"copying skill {n} into {container}:{dst}")
+        subprocess.run(
+            ["docker", "exec", container, "rm", "-rf", dst],
+            stdout=subprocess.DEVNULL,
+            check=True,
+        )
+        subprocess.run(
+            ["docker", "exec", container, "mkdir", "-p", dst],
+            stdout=subprocess.DEVNULL,
+            check=True,
+        )
+        subprocess.run(
+            ["docker", "cp", f"{src}/.", f"{container}:{dst}/"],
+            stdout=subprocess.DEVNULL,
+            check=True,
+        )