feat: logging overhaul, MCP server factory, lazy imports

[AKKI0511]

Summary

• Refactored logging across the codebase to follow project conventions.
• Introduced factory method for the MCP registry server.
• Added lazy imports for optional deps; simplified package __init__ exports.
• Updated docs/examples to new logging approach.
• Formatted and expanded tests; updated CHANGELOG and dependencies.

Motivation

• Reduce log noise and standardize semantics.
• Decouple MCP server construction from module import side effects.
• Avoid import-time failures for optional payment deps.

Changes

• Agents: Simplified logging; removed unnecessary logs. (agentconnect/agents/*)
• Clients/Communication/Config: Standardized logging. (agentconnect/clients, agentconnect/communication, agentconnect/config)
• Core/Registry: Streamlined logging; no redundant messages. (agentconnect/core/registry/*)
• Core Agent + API: Lazy import optional payment deps in agentconnect/core/agent.py; exposed BaseAgent via agentconnect/core/__init__.py.
• Package Init: Removed eager imports; added lazy optional imports. (agentconnect/__init__.py)
• MCP: Factory method for registry MCP server; removed module-level logger. (agentconnect/mcp/registry_mcp_server.py, agentconnect/mcp/__init__.py)
• Servers: Use nested uvicorn.error.agentconnect.registry logger; no manual logging config. (agentconnect/servers/registry_api_server.py)
• Utils: Removed legacy utils/logging_config.py; updated logging across utils. (agentconnect/utils/*)
• CLI: Temporary --verbose setup. (agentconnect/cli.py)
• Docs/Examples: Removed references to old utils logging; formatted docs Python. (docs/**, examples/**)
• Tests: Formatted and added tests/imports and tests/logging. (tests/**)
• Meta: Added AGENTS.md; updated CHANGELOG.md; updated poetry.lock.

Breaking Changes

• Removed agentconnect/utils/logging_config.py.
  • Migration: use standard logging.getLogger(__name__) and the new conventions.

Checklist

• Conventional commit messages
• Code formatted and linted (Black/Flake8)
• Tests added/updated and passing
• Docs build clean; API nav working
• CHANGELOG updated
• No secrets committed
• Examples updated

CHANGELOG Excerpt

• Added: MCP registry server factory; BaseAgent export in core.
• Changed: Logging refactor across modules; CLI --verbose; server logger to nested uvicorn.error.agentconnect.registry.
• Removed: agentconnect/utils/logging_config.py.
• Chore: Update dependencies (poetry.lock), docs/examples formatting, new tests, AGENTS.md.