Implementation of the four-level automation profile precedence chain
(plan > action > project > global) as defined in the v3.5.0 specification.
Core implementation (src/):
- PrecedenceSource StrEnum with PLAN, ACTION, PROJECT, GLOBAL levels
- PrecedenceResolution frozen dataclass capturing full resolution state
- resolve_precedence_chain() with plan > action > project > global logic
- _resolve_global_profile() with explicit > env var > default fallback
- Comprehensive debug logging for observability
BDD tests (features/):
- automation_profile_precedence_chain.feature: 30 scenarios covering all
16 combinations of plan/action/project/global configurations plus edge
cases, logging verification, enum values, env var override, and custom registry
- step definitions with proper log handler cleanup via context._cleanup_handlers
CI compliance fixes (bd8b6748):
- ruff format applied to step definitions (fixes CI lint gate)
- CHANGELOG.md updated with accurate 4-level chain description
- test_reports/ artifacts removed; directory added to .gitignore
- tdd_a2a_sdk_dependency.feature reverted to use correct Client import
ISSUES CLOSED: #8234
