Release 0.6.0

Added

Extension System

• ExtensionManager / ExtensionPoint - Added a unified extension-point framework for discoverer, middleware, acl, span_exporter, and module_validator
• Extension wiring - Added apply() support to connect registered extensions into Registry and Executor

Async Task & Cancellation

• AsyncTaskManager - Added background task orchestration with status tracking, cancellation, concurrency limits, shutdown, and cleanup
• TaskStatus / TaskInfo - Added task lifecycle enum and metadata dataclass for async task management
• CancelToken / ExecutionCancelledError - Added cooperative cancellation primitives and integrated cancellation checks into executor flows

Trace Context & Observability

• TraceContext / TraceParent - Added W3C Trace Context utilities for inject(), extract(), and strict parsing via from_traceparent()
• Context.create(trace_parent=...) - Added distributed-tracing entry support by accepting inbound trace context
• OTLPExporter top-level export - Added OTLP exporter re-exports in observability and top-level public API

Registry Enhancements

• Custom discoverer/validator hooks - Added set_discoverer() and set_validator() integration paths
• Module describe support - Added Registry.describe() for human-readable module descriptions
• Hot-reload APIs - Added watch(), unwatch(), and file-change handling helpers for extension directories
• Validation constants/protocols - Added MAX_MODULE_ID_LENGTH, RESERVED_WORDS, Discoverer, and ModuleValidator exports

Changed

Public API Surface

• Expanded top-level apcore exports to include cancellation, extensions, async task types, trace context types, additional registry protocols/constants, and new error classes

Error System

• Added ModuleExecuteError and InternalError to the framework error hierarchy and exports
• Extended ErrorCodes with additional constants used by newer execution/extension paths

Fixed

Execution & Redaction

• executor - Added recursive _secret_ key redaction for nested dictionaries
• executor - Preserved explicit cancellation semantics by re-raising ExecutionCancelledError

Import Graph Robustness

• Reduced import-coupling risk across middleware/observability/trace typing paths while preserving existing runtime behavior and public interfaces