feat: Migrate Agentic CLI UI to use REST API client

[aarora79]

The Agentic CLI UI in cli/src/ should be migrated to use the REST API client library in api/ directory instead of shell scripts like service_mgmt.sh. This will provide a consistent, well-tested interface for all CLI operations.

Background

The api/ directory contains REST API client implementations:

• api/registry_client.py - Core registry client for API interactions
• api/registry_management.py - Registry management operations

Current State

The CLI currently relies on shell scripts (e.g., service_mgmt.sh, agent_mgmt.sh) which it should not. Instead, it should use the REST API client directly.

The following functionality is currently available through the REST API client:

• Server management (register, toggle, remove, health checks)
• Agent management (register, update, delete, discover)
• Anthropic Registry API support (list servers, versions)
• Semantic search across servers, tools, and agents

Blocked By

This issue is dependent on #247 to be completed first.

The following functionality is NOT yet available through the REST API and needs to be added in #247:

• User management operations
• Token generation and retrieval (/tokens/generate)
• Authentication flow handling

Until #247 is complete, the CLI cannot fully migrate to using the REST API client for all operations.

Scope

Once #247 is complete, update cli/src/ to:

1. Import and use the REST API client from api/registry_client.py
2. Replace shell script calls with client method calls
3. Leverage consistent error handling from the client library
4. Remove dependency on shell scripts for API interactions

Files to Update

• cli/src/commands/executor.ts
• cli/src/agent/tools.ts
• cli/src/agent/agentRunner.ts
• Other files calling shell scripts for API operations

Acceptance Criteria

• CLI uses REST API client for all server management operations
• CLI uses REST API client for all agent management operations
• CLI uses REST API client for authentication/token operations (after Add management APIs to replace shell scripts #247)
• No shell script dependencies for API interactions remain in CLI
• All existing CLI functionality continues to work