feat(agent): Phase 36 - Agent Self-Healing, Plan Drift Detection & Auto-Rollback

[De-pitcher]

Summary

Implements Phase 36: Agent Self-Healing, Plan Drift Detection & Auto-Rollback for agentcli.

Core Capabilities

• Plan Drift & Cycle Detector (\PlanDriftDetector\ in \�gentcli/agent/drift_detector.py):
  • Continuous action recording and execution signature tracking.
  • Multi-heuristic loop detection: consecutive repeated errors on identical actions, ping-pong / oscillating step sequences (\A <-> B), and repeated identical tool invocations.
  • Quantified drift score calculation (0.0 to 1.0) and classification into \LOW, \MODERATE, and \CRITICAL\ drift severities.
• Auto-Healing & Rollback Manager (\AutoHealingManager\ in \�gentcli/agent/rollback.py):
  • Pre-step multi-file state snapshotting before mutative operations.
  • Automatic rollback upon step failure, consecutive errors, loop detection, or critical drift.
  • Contextual recovery strategy synthesis to guide the planner away from failing patterns and propose alternative tool paths.
• Loop Lifecycle Events (\�gentcli/agent/events.py):
  • \DriftDetectedEvent: Emitted when drift severity elevates or cycles are detected.
  • \AutoHealingRollbackEvent: Emitted when filesystem rollbacks occur.
  • \StrategyRecoveryEvent: Emitted when dynamic recovery prompt instructions are synthesized.
• AgentLoop & Session Integration (\�gentcli/agent/loop.py, \�gentcli/session.py):
  • Wired drift detection and auto-healing into the Plan → Act → Reflect execution pipeline.
  • Integrated synthesized recovery prompts into re-planning loops.
• CLI & TUI Commands (\�gentcli/cli.py, \�gentcli/ui/prompt.py, \�gentcli/ui/tui_app.py):
  • /healing\ command support (\status,
    ollback [id],
    eset, \enable, \disable) with argument completion.
  • Rich and plain-text visual rendering in console renderer.
• Test Suite:
  • Comprehensive unit and integration test suite in \ ests/test_phase36_self_healing.py\ (17 tests passing).

Verification

• \python -m ruff check agentcli tests: Passed (0 errors)
• \python -m mypy .: Passed (0 errors across 130 source files)
• \python -m pytest tests/test_phase36_self_healing.py tests/test_session.py tests/test_agent_loop.py tests/test_cli.py: Passed (119/119 tests passing)