feat: add providers CLI command for managing AI providers

New commands:
- smarttools providers list - List all providers with status
- smarttools providers check - Check which providers are available
- smarttools providers add <name> <command> - Add/update provider
- smarttools providers remove <name> - Remove provider
- smarttools providers test <name> - Test a provider

Features:
- Shows [+] for available, [-] for missing providers
- Mock provider always shows as available (built-in)
- Helpful installation hints when no providers found
- Can add custom providers (Ollama, local scripts, etc.)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/smarttools/cli.py

@@ -2,10 +2,12 @@
 
 import argparse
 import sys
+from pathlib import Path
 
 from . import __version__
 from .tool import list_tools, load_tool, save_tool, delete_tool, Tool, ToolArgument, PromptStep, CodeStep
 from .ui import run_ui
+from .providers import load_providers, add_provider, delete_provider, Provider, call_provider
 
 
 def cmd_list(args):
@@ -336,6 +338,107 @@ echo "input" | {args.name}
         return 0
 
 
+def cmd_providers(args):
+    """Manage AI providers."""
+    import shutil
+
+    if args.providers_cmd == "list":
+        providers = load_providers()
+        print(f"Configured providers ({len(providers)}):\n")
+        for p in providers:
+            # Mock provider is always available
+            if p.name.lower() == "mock":
+                print(f"  [+] {p.name}")
+                print(f"      Command: (built-in)")
+                print(f"      Status: OK (always available)")
+                if p.description:
+                    print(f"      Info: {p.description}")
+                print()
+                continue
+
+            # Check if command exists
+            cmd_parts = p.command.split()[0]
+            cmd_expanded = cmd_parts.replace("$HOME", str(Path.home())).replace("~", str(Path.home()))
+            exists = shutil.which(cmd_expanded) is not None or Path(cmd_expanded).exists()
+            status = "OK" if exists else "NOT FOUND"
+            status_icon = "+" if exists else "-"
+
+            print(f"  [{status_icon}] {p.name}")
+            print(f"      Command: {p.command}")
+            print(f"      Status: {status}")
+            if p.description:
+                print(f"      Info: {p.description}")
+            print()
+        return 0
+
+    elif args.providers_cmd == "add":
+        name = args.name
+        command = args.command
+        description = args.description or ""
+
+        provider = Provider(name, command, description)
+        add_provider(provider)
+        print(f"Provider '{name}' added/updated.")
+        return 0
+
+    elif args.providers_cmd == "remove":
+        name = args.name
+        if delete_provider(name):
+            print(f"Provider '{name}' removed.")
+            return 0
+        else:
+            print(f"Provider '{name}' not found.")
+            return 1
+
+    elif args.providers_cmd == "test":
+        name = args.name
+        print(f"Testing provider '{name}'...")
+        result = call_provider(name, "Say 'hello' and nothing else.", timeout=30)
+        if result.success:
+            print(f"SUCCESS: {result.text[:200]}...")
+        else:
+            print(f"FAILED: {result.error}")
+        return 0 if result.success else 1
+
+    elif args.providers_cmd == "check":
+        providers = load_providers()
+        print("Checking all providers...\n")
+        available = []
+        missing = []
+
+        for p in providers:
+            # Mock provider is always available (handled specially)
+            if p.name.lower() == "mock":
+                available.append(p.name)
+                print(f"  [+] {p.name}: OK (built-in)")
+                continue
+
+            cmd_parts = p.command.split()[0]
+            cmd_expanded = cmd_parts.replace("$HOME", str(Path.home())).replace("~", str(Path.home()))
+            exists = shutil.which(cmd_expanded) is not None or Path(cmd_expanded).exists()
+
+            if exists:
+                available.append(p.name)
+                print(f"  [+] {p.name}: OK")
+            else:
+                missing.append(p.name)
+                print(f"  [-] {p.name}: NOT FOUND ({cmd_parts})")
+
+        print(f"\nSummary: {len(available)} available, {len(missing)} missing")
+        if len(available) == 1 and available[0] == "mock":
+            print(f"\nNo real AI providers found. Install one of these:")
+            print(f"  - claude: npm install -g @anthropic-ai/claude-cli")
+            print(f"  - codex: pip install openai-codex")
+            print(f"  - gemini: pip install google-generative-ai")
+            print(f"\nMeanwhile, use mock provider for testing:")
+            print(f"  echo 'test' | summarize --provider mock")
+        elif missing:
+            print(f"\nAvailable providers: {', '.join(available)}")
+        return 0
+
+    return 0
+
+
 def main():
     """Main CLI entry point."""
     parser = argparse.ArgumentParser(
@@ -405,6 +508,38 @@ def main():
     p_docs.add_argument("-e", "--edit", action="store_true", help="Edit/create README in $EDITOR")
     p_docs.set_defaults(func=cmd_docs)
 
+    # 'providers' command
+    p_providers = subparsers.add_parser("providers", help="Manage AI providers")
+    providers_sub = p_providers.add_subparsers(dest="providers_cmd", help="Provider commands")
+
+    # providers list
+    p_prov_list = providers_sub.add_parser("list", help="List all providers and their status")
+    p_prov_list.set_defaults(func=cmd_providers)
+
+    # providers check
+    p_prov_check = providers_sub.add_parser("check", help="Check which providers are available")
+    p_prov_check.set_defaults(func=cmd_providers)
+
+    # providers add
+    p_prov_add = providers_sub.add_parser("add", help="Add or update a provider")
+    p_prov_add.add_argument("name", help="Provider name")
+    p_prov_add.add_argument("command", help="Command to run (e.g., 'claude -p')")
+    p_prov_add.add_argument("-d", "--description", help="Provider description")
+    p_prov_add.set_defaults(func=cmd_providers)
+
+    # providers remove
+    p_prov_remove = providers_sub.add_parser("remove", help="Remove a provider")
+    p_prov_remove.add_argument("name", help="Provider name")
+    p_prov_remove.set_defaults(func=cmd_providers)
+
+    # providers test
+    p_prov_test = providers_sub.add_parser("test", help="Test a provider")
+    p_prov_test.add_argument("name", help="Provider name")
+    p_prov_test.set_defaults(func=cmd_providers)
+
+    # Default for providers with no subcommand
+    p_providers.set_defaults(func=lambda args: cmd_providers(args) if args.providers_cmd else (setattr(args, 'providers_cmd', 'list') or cmd_providers(args)))
+
     args = parser.parse_args()
 
     # If no command, launch UI