…builtins alias

- dispatch: add _is_tool_installed() pre-flight check (importlib.util.find_spec)
  so 'devforge guard ...' on an uninstalled tool shows a clear
  'not installed — run pip install devforge[guard]' message instead of
  silently exiting 1 with a raw Python ModuleNotFoundError trace.
  The previous except FileNotFoundError was dead code: the error occurs
  inside the subprocess, not at Popen launch time.
- install all: use canonical devforge[all] extra instead of joining all
  tool keys into a comma-separated extras string (fragile; diverges if
  TOOLS and pyproject.toml [all] ever drift).
- Remove 'import builtins as _builtins' workaround; no builtin shadowing
  exists, so list() is fine throughout.
- Remove unused ctx: typer.Context parameter from dispatch inner function.
- Tests: 17/17 green; new TestIsToolInstalled + dispatch install-hint +
  install-all-extra assertion tests cover the fixed paths.

…ve cli.py merge conflicts keeping the install-all + dispatch improvements

…cile history)

…ilure trap)

The per-tool subcommands (guard, sql, deploy, ...) used a typer Argument
for args, which made typer reject any token beginning with `-` as an
unknown option BEFORE the underlying tool ever ran. So `devforge guard
--config x.yaml` failed with "No such option" and the tool silently never
executed — the hub's known silent-failure/observability trap.

Register each dispatch command with ignore_unknown_options +
allow_extra_args and forward ctx.args to the underlying `python -m
<pkg>` invocation. Positional args and flags now reach the tool. Added a
regression test (test_dispatch_forwards_tool_flags) and the
cowork-auto-pr workflow so the improvement is delivered as a PR.