feat(ui): add /history to welcome banner and update input handling

Author: om-mapari

shello_cli/ui/ui_renderer.py

@@ -202,6 +202,9 @@ def display_help():
     commands_table.add_row("/quit", "Exit the application")
     commands_table.add_row("/exit", "Exit the application")
     commands_table.add_row("/new", "Start a new conversation")
+    commands_table.add_row("/history", "Browse and resume past sessions")
+    commands_table.add_row("/history clear", "Delete all session history")
+    commands_table.add_row("/history delete", "Delete a specific session")
     commands_table.add_row("/switch", "Switch between AI providers")
     commands_table.add_row("/update", "Update to the latest version")
     commands_table.add_row("/about", "Show information about Shello CLI")
@@ -277,6 +280,7 @@ def print_welcome_banner(user_info, version):
     console.print("  [bold bright_blue]/about[/bold bright_blue] [bright_black]─[/bright_black] [white]Show information about Shello CLI[/white]")
     console.print("  [bold bright_blue]/quit[/bold bright_blue] [bright_black]─[/bright_black] [white]Exit the application[/white]")
     console.print("  [bold bright_blue]/new[/bold bright_blue] [bright_black]─[/bright_black] [white]Start a new conversation[/white]")
+    console.print("  [bold bright_blue]/history[/bold bright_blue] [bright_black]─[/bright_black] [white]Browse and resume past sessions[/white]")
     console.print("  [bold bright_blue]/switch[/bold bright_blue] [bright_black]─[/bright_black] [white]Switch between AI providers[/white]")
     console.print("  [bold bright_blue]/help[/bold bright_blue] [bright_black]─[/bright_black] [white]Show keyboard shortcuts and help[/white]")
     console.print("  [bold bright_blue]↑/↓[/bold bright_blue] [bright_black]─[/bright_black] [white]Navigate command history[/white]")

shello_cli/ui/user_input.py

@@ -81,7 +81,7 @@ class BAICompleter(Completer):
 
     def __init__(self, history_obj=None):
         self.history = history_obj
-        self.commands = ['/quit', '/exit', '/new', '/about', '/help']
+        self.commands = ['/quit', '/exit', '/new', '/about', '/help', '/history']
         self.common_phrases = [
             'can you help me with',
             'how do I',