refactor: Major upgrade to v5.1b6 - AWS SSM support & Distributed Architecture

Core & Protocols:
- Native AWS SSM support added (aws ssm start-session).
- Improved Pexpect logic for ssm, kubectl, and docker.
- Cleaned connection success messages (omitting ports for non-IP protocols).

gRPC Layer:
- Migrated gRPC modules to 'connpy/grpc_layer/'.
- Implemented dynamic node naming (e.g. ssm-i-xxxx@aws) for accurate server-side logging.
- Added automatic sys.path resolution for gRPC generated modules.
- Enhanced InteractNode response with initial connection status.

Printer & Concurrency:
- Implemented ThreadLocalStream for isolated thread-safe output.
- Self-healing Console objects to prevent 'closed file' errors in test/async environments.
- Capture clean plugin output in remote executions.

AI & Services:
- Improved tool registration and debug visualization.
- Restored native dictionary returns for AI tools to fix Web UI rendering.
- Increased backup retention to 100 copies in SyncService.
- Silenced noisy auto-sync CLI messages.

Quality & Docs:
- Total tests: 267 (all passing).
- New test suites for gRPC layer and printer concurrency.
- Updated .gitignore to exclude internal planning docs.
- Full technical documentation regenerated with pdoc.

connpy/grpc_layer/__init__.py

@@ -0,0 +1,8 @@
+import sys
+import os
+
+# gRPC generated files use absolute imports that assume their directory is in sys.path.
+# We add this directory to sys.path to allow imports like 'import connpy_pb2' to succeed.
+current_dir = os.path.dirname(os.path.abspath(__file__))
+if current_dir not in sys.path:
+    sys.path.insert(0, current_dir)