feat: Add -h/--help option to all functions

Adds a `usage` variable and help flag handling to all public functions in `ollama_bash_lib.sh`, allowing users to get usage information by calling any function with `-h` or `--help`.

The implementation follows the pattern of the existing `ollama_app_turbo` function as requested.

- For functions with arguments, the help flag is detected anywhere in the argument list.
- For functions without arguments, only the help flag is accepted as a valid argument, with errors for any other arguments.

Also adds a new verification script, `demos/test-help.sh`, to test the new functionality across all public functions.

Author: google-labs-jules[bot]

demos/test-help.sh

@@ -0,0 +1,80 @@
+#!/usr/bin/env bash
+#
+# Test script for -h/--help option on all functions in ollama_bash_lib.sh
+#
+
+# Source the library
+# shellcheck source=../ollama_bash_lib.sh
+source "$(dirname "$0")/../ollama_bash_lib.sh"
+
+# List of all public functions in the library
+functions=(
+  ollama_api_get
+  ollama_api_post
+  ollama_api_ping
+  ollama_generate_json
+  ollama_generate
+  ollama_generate_stream_json
+  ollama_generate_stream
+  ollama_messages
+  ollama_messages_add
+  ollama_messages_clear
+  ollama_messages_count
+  ollama_tools_add
+  ollama_tools
+  ollama_tools_count
+  ollama_tools_clear
+  ollama_tools_is_call
+  ollama_tools_run
+  ollama_chat_json
+  ollama_chat
+  ollama_chat_stream
+  ollama_chat_stream_json
+  ollama_list
+  ollama_list_json
+  ollama_list_array
+  ollama_model_random
+  ollama_model_unload
+  ollama_ps
+  ollama_ps_json
+  ollama_show
+  ollama_show_json
+  ollama_app_installed
+  ollama_app_turbo
+  ollama_app_vars
+  ollama_app_version
+  ollama_app_version_json
+  ollama_app_version_cli
+  ollama_thinking
+  ollama_lib_about
+  ollama_lib_version
+  ollama_eval
+)
+
+echo "--- Testing -h for all functions (first argument) ---"
+for func in "${functions[@]}"; do
+  printf "\n--- Testing %s -h ---\n" "$func"
+  "$func" -h
+done
+
+echo -e "\n\n--- Testing --help for all functions (first argument) ---"
+for func in "${functions[@]}"; do
+  printf "\n--- Testing %s --help ---\n" "$func"
+  "$func" --help
+done
+
+echo -e "\n\n--- Testing help flag in various positions for functions with arguments ---"
+printf "\n--- Testing ollama_generate \"model\" -h ---\n"
+ollama_generate "model" -h
+printf "\n--- Testing ollama_generate \"model\" \"prompt\" --help ---\n"
+ollama_generate "model" "prompt" --help
+printf "\n--- Testing ollama_eval \"task\" -h \"model\" ---\n"
+ollama_eval "task" -h "model"
+
+echo -e "\n\n--- Testing error handling for no-argument functions ---"
+printf "\n--- Testing ollama_api_ping foo ---\n"
+ollama_api_ping foo
+printf "\n--- Testing ollama_list bar baz ---\n"
+ollama_list bar baz
+
+echo -e "\n\n--- Test complete ---"