[rosspeili]

Fixes #93

Description

Enhances the standard BreakObserver (preset: break) with sliding-window trajectory cycle detection, cognitive deadlock sensors, FinOps token burn guards, and cryptographic non-repudiation proofs while preserving 100% backward compatibility for legacy max_identical_intents.

What changed & why:

• Sliding-Window Trajectory Locality ($K=8$): Replaces blunt global counts with a local rolling window, preventing false-positive trip alerts on long-running healthy agent workflows.
• Cycle Topologies Detected:
  • Action Fixation (1-cycle): Consecutive repetition of identical tool and normalized argument signatures ($A \to A \to A$).
  • State Oscillation (2-cycle): Alternating conflicting state toggles across turns ($A \leftrightarrow B \leftrightarrow A \leftrightarrow B$).
  • Execution Choreography (3-cycle): Multi-step repetitive loop patterns ($A \to B \to C \to A \to B \to C$).
• Cognitive Deadlock Sensors:
  • Error Status Churn: Tracks consecutive identical SHA-256 error fingerprints across tool responses.
  • Reasoning Inertia: Detects cognitive rutting when consecutive turn thoughts exhibit $\ge 85%$ text similarity ratio via difflib.SequenceMatcher.
• FinOps Loop Burn-Velocity Guard: Accumulates wasted tokens across repeating loops and alerts on burn-rate spikes when max_cycle_token_waste is exceeded.
• EU AI Act Art. 14 Cryptographic Proofs: Records non-repudiable SHA-256 spine hashes (cycle_entry_hash, cycle_recurrence_hash) in observer.alert payloads for verifiable algorithmic deadlock auditing.
• Actionable Remedial Directives: Every alert emits structured remedial_directive steering strings with prompt-level recovery guidance (prefixed BREAK:).
• Remedial Actions & Escalation Wiring: Supports action: "alert_only" (default), action: "pause" (appends break_pause rule and trips session state), and full integration with profile.escalations[] (on: observer.alert).
• Audit Report & Scorecard: Enriches audit reports with scorecard.observers = {alerts, loop_cycles} and finding COGNITIVE_CYCLE_DETECTED (severity: warn).

Type

• Bug fix
• Core framework — session, spine, constraints, identity, audit report
• CLI
• Integration — sequencer, hosts, membrane, observers, exporters
• Documentation
• Examples
• Packaging / CI

Checklist

• Linked issue (Fixes #93)
• pytest passes (300/300 passed)
• black aura tests — no diff (121 files clean)
• flake8 aura tests — clean (0 errors, 0 warnings)
• CHANGELOG.md updated when user-visible behavior changes

Test plan

1. Unit & Edge Case Suite (pytest tests/test_observer_break_loop.py):
   • 15/15 unit tests passed covering legacy backward compatibility, 1/2/3-cycle topologies, error churn, reasoning inertia, sliding window locality, FinOps token burn guard, cryptographic spine hashes, escalation trigger firing, audit report scorecard & findings synthesis, Tier 2 watchdog callback mode, configured pause/circuit-break enforcement actions, and observer summary metrics.
2. Dedicated High-Throughput Stress Suite (python scripts/aura_break_loop_stress_sim.py):
   • 5/5 stress scenarios passed: 5,000 events processed at 1,936 eps with 0 memory leaks, noisy oscillation detection, choreography burn-velocity spike, error churn stress, and cryptographic hash chain verification.
3. Full Repository Regression Suite (pytest):
   • All 300 tests across the entire repository passed in 63.72s with zero failures.
4. Linting & Code Formatting:
   • black --check aura tests scripts: 121 files verified clean.
   • flake8 aura tests scripts: 0 errors, 0 warnings.