feat: enhance help command UX, completions, and CLI tips

- Expanded help command to accept:
  - `-k/--key` for detailed help on a specific command
  - `-t/--tag` for tag-filtered listings
  - `-T/--tldr` for quick usage examples
- Updated TLDR flag to support `-T` short form and refined help text.
- Improved `_render_help()` to show contextual CLI tips after help or TLDR output.
- Adjusted completer to yield both upper and lower case completions without mutating the prefix.
- Standardized CLI tip strings in root/arg parsers to reference `help` and `preview` subcommands instead of menu `run ?` syntax.
- Passed `options_manager` to history/help/exit commands for consistency.
- Allowed `help_command` to display TLDR examples when invoked without a key.
- Added test assertions for help command key/alias consistency.
- Bumped version to 0.1.82.

tests/test_falyx/test_help.py

@@ -6,6 +6,8 @@ from falyx import Falyx
 @pytest.mark.asyncio
 async def test_help_command(capsys):
     flx = Falyx()
+    assert flx.help_command.arg_parser.aliases[0] == "HELP"
+    assert flx.help_command.arg_parser.command_key == "H"
     await flx.run_key("H")
 
     captured = capsys.readouterr()