Function detect_conversation_cycle 

pub fn detect_conversation_cycle(
    coherence_history: &[f64],
    window: usize,
    threshold: f64,
) -> ConversationState

Detect if coherence changes indicate a circular/stuck conversation.

Examines the last window entries of the coherence history and classifies the trajectory as converging, diverging, stuck, or oscillating.

Arguments

• coherence_history: Full history of coherence values (one per tick).
• window: Number of recent entries to examine.
• threshold: Minimum meaningful change (below this = stuck).

Implementation

Dispatches through clawft_treecalc::triage_trajectory first (Finding #8 in docs/eml-treecalc-swap-sites.md): the trajectory is classified as Atom (flat), Sequence (monotone), or Branch (oscillating) by its sign-of-difference pattern. The treecalc form then drives which ConversationState is returned, and the per-state metrics (rate, net_change, max_swing) are computed from the same recent window. This replaces the nested threshold arithmetic with a structural dispatch that’s easier to extend (e.g. a future Atom sub-classifier distinguishing “never-started” from “plateaued”).