feat(phase-ai): add discard-matters deck-feature axis + DiscardPayoffPolicy

crates/phase-ai/src/config.rs

@@ -541,6 +541,10 @@ pub struct PolicyPenalties {
     /// reducer — the discount should be deployed first.
     #[serde(default = "default_cost_reduction_defer_penalty")]
     pub cost_reduction_defer_penalty: f64,
+    /// CR 701.9: card-equivalent value of discarding into one active "whenever
+    /// you discard" engine (preference band, per engine).
+    #[serde(default = "default_discard_payoff_bonus")]
+    pub discard_payoff_bonus: f64,
 }
 
 impl Default for PolicyPenalties {
@@ -618,6 +622,7 @@ impl Default for PolicyPenalties {
             draw_payoff_bonus: default_draw_payoff_bonus(),
             cost_reduction_deploy_bonus: default_cost_reduction_deploy_bonus(),
             cost_reduction_defer_penalty: default_cost_reduction_defer_penalty(),
+            discard_payoff_bonus: default_discard_payoff_bonus(),
         }
     }
 }
@@ -752,6 +757,9 @@ fn default_cost_reduction_deploy_bonus() -> f64 {
 fn default_cost_reduction_defer_penalty() -> f64 {
     -0.25
 }
+fn default_discard_payoff_bonus() -> f64 {
+    0.6
+}
 fn default_sacrifice_token_cost() -> f64 {
     0.5
 }
@@ -909,6 +917,10 @@ pub const UNTUNED_POLICY_PENALTY_FIELDS: &[(&str, &str)] = &[
         "CR 601.2f sequencing nudge for casting past a cheaper unplayed reducer — \
          awaiting a paired-seed ai-gate calibration.",
     ),
+    (
+        "discard_payoff_bonus",
+        "CR 701.9 per-engine discard-payoff weight — awaiting a paired-seed ai-gate calibration.",
+    ),
     (
         "poison_clock_pressure",
         "CR 104.3d win-detector weight — a critical-band term whose magnitude is \

crates/phase-ai/src/features/mod.rs

@@ -14,6 +14,7 @@ pub mod commitment;
 pub mod control;
 pub mod cost_reduction;
 pub mod devotion;
+pub mod discard_matters;
 pub mod draw_matters;
 pub mod enchantments;
 pub mod energy;
@@ -40,6 +41,7 @@ pub use blink::BlinkFeature;
 pub use control::ControlFeature;
 pub use cost_reduction::CostReductionFeature;
 pub use devotion::DevotionFeature;
+pub use discard_matters::DiscardMattersFeature;
 pub use draw_matters::DrawMattersFeature;
 pub use enchantments::EnchantmentsFeature;
 pub use energy::EnergyFeature;
@@ -98,6 +100,9 @@ pub struct DeckFeatures {
     pub graveyard_types: GraveyardTypesFeature,
     /// CR 121.1: "whenever you draw" payoff density (draw sources + engines).
     pub draw_matters: DrawMattersFeature,
+    /// CR 701.9: "whenever you discard" payoff density (self-discard outlets +
+    /// engines). Disjoint from `hand_disruption`, which scores OPPONENT discard.
+    pub discard_matters: DiscardMattersFeature,
     /// Declaration-derived: the deck's declared bracket tier. Unlike the
     /// other fields here, this is not structurally detected from card text —
     /// it is a per-deck declaration set at deck-analysis time from deck
@@ -147,6 +152,7 @@ impl DeckFeatures {
             poison: poison::detect(deck),
             graveyard_types: graveyard_types::detect(deck),
             draw_matters: draw_matters::detect(deck),
+            discard_matters: discard_matters::detect(deck),
             bracket_tier: tier,
         }
     }