feat: redesign help command, improve completer UX, and document Falyx CLI

- Renamed CLI subcommand from `list` to `help` for clarity and discoverability.
- Added `--key` and `--tldr` support to the `help` command for detailed and example-based output.
- Introduced `FalyxMode.HELP` to clearly delineate help-related behavior.
- Enhanced `_render_help()` to support:
  - Tag filtering (`--tag`)
  - Per-command help (`--key`)
  - TLDR example rendering (`--tldr`)
- Updated built-in Help command to:
  - Use `FalyxMode.HELP` internally
  - Provide fallback messages for missing help or TLDR data
  - Remove `LIST` alias (replaced by `help`)
- Documented `FalyxCompleter`:
  - Improved docstrings for public methods and completions
  - Updated internal documentation to reflect all supported completion cases
- Updated `CommandArgumentParser.render_tldr()` with fallback message for missing TLDR entries.
- Updated all parser docstrings and variable names to reference `help` (not `list`) as the proper CLI entrypoint.
- Added test coverage:
  - `tests/test_falyx/test_help.py` for CLI `help` command with `tag`, `key`, `tldr`, and fallback scenarios
  - `tests/test_falyx/test_run.py` for basic CLI parser integration
- Bumped version to 0.1.81

tests/test_falyx/test_help.py

@@ -0,0 +1,94 @@
+import pytest
+
+from falyx import Falyx
+
+
+@pytest.mark.asyncio
+async def test_help_command(capsys):
+    flx = Falyx()
+    await flx.run_key("H")
+
+    captured = capsys.readouterr()
+    assert "Show this help menu" in captured.out
+
+
+@pytest.mark.asyncio
+async def test_help_command_with_new_command(capsys):
+    flx = Falyx()
+
+    async def new_command(falyx: Falyx):
+        pass
+
+    flx.add_command(
+        "N",
+        "New Command",
+        new_command,
+        aliases=["TEST"],
+        help_text="This is a new command.",
+    )
+    await flx.run_key("H")
+
+    captured = capsys.readouterr()
+    assert "This is a new command." in captured.out
+    assert "TEST" in captured.out and "N" in captured.out
+
+
+@pytest.mark.asyncio
+async def test_render_help(capsys):
+    flx = Falyx()
+
+    async def sample_command(falyx: Falyx):
+        pass
+
+    flx.add_command(
+        "S",
+        "Sample Command",
+        sample_command,
+        aliases=["SC"],
+        help_text="This is a sample command.",
+    )
+    await flx._render_help()
+
+    captured = capsys.readouterr()
+    assert "This is a sample command." in captured.out
+    assert "SC" in captured.out and "S" in captured.out
+
+
+@pytest.mark.asyncio
+async def test_help_command_by_tag(capsys):
+    flx = Falyx()
+
+    async def tagged_command(falyx: Falyx):
+        pass
+
+    flx.add_command(
+        "T",
+        "Tagged Command",
+        tagged_command,
+        tags=["tag1"],
+        help_text="This command is tagged.",
+    )
+    await flx.run_key("H", args=("tag1",))
+
+    captured = capsys.readouterr()
+    assert "tag1" in captured.out
+    assert "This command is tagged." in captured.out
+    assert "HELP" not in captured.out
+
+
+@pytest.mark.asyncio
+async def test_help_command_empty_tags(capsys):
+    flx = Falyx()
+
+    async def untagged_command(falyx: Falyx):
+        pass
+
+    flx.add_command(
+        "U", "Untagged Command", untagged_command, help_text="This command has no tags."
+    )
+    await flx.run_key("H", args=("nonexistent_tag",))
+
+    captured = capsys.readouterr()
+    print(captured.out)
+    assert "nonexistent_tag" in captured.out
+    assert "Nothing to show here" in captured.out

tests/test_falyx/test_run.py

@@ -0,0 +1,19 @@
+import sys
+
+import pytest
+
+from falyx import Falyx
+from falyx.parser import get_arg_parsers
+
+
+@pytest.mark.asyncio
+async def test_run_basic(capsys):
+    sys.argv = ["falyx", "run", "-h"]
+    falyx_parsers = get_arg_parsers()
+    assert falyx_parsers is not None, "Falyx parsers should be initialized"
+    flx = Falyx()
+    with pytest.raises(SystemExit):
+        await flx.run(falyx_parsers)
+
+    captured = capsys.readouterr()
+    assert "Run a command by its key or alias." in captured.out