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.

falyx/completer.py

@@ -120,7 +120,6 @@ class FalyxCompleter(Completer):
         Yields:
             Completion: Matching keys or aliases from all registered commands.
         """
-        prefix = prefix.upper()
         keys = [self.falyx.exit_command.key]
         keys.extend(self.falyx.exit_command.aliases)
         if self.falyx.history_command:
@@ -134,7 +133,9 @@ class FalyxCompleter(Completer):
             keys.extend(cmd.aliases)
         for key in keys:
             if key.upper().startswith(prefix):
-                yield Completion(key, start_position=-len(prefix))
+                yield Completion(key.upper(), start_position=-len(prefix))
+            elif key.lower().startswith(prefix):
+                yield Completion(key.lower(), start_position=-len(prefix))
 
     def _ensure_quote(self, text: str) -> str:
         """