Retune the case ramp, and let leading a phase earn experience

The ramp made every phase after the first Difficult (halving the lead's skill) and
stacked a cumulative -5% on top. Separated in phaseRampFor() in rules.mjs:
difficulty belongs to the phase (only Containment is Difficult, and it does not
also ramp), the modifier is attrition (-5 a phase, capped at -15).

  lead 55%   was 55 -> 22 -> 17 -> 12 -> 7      now 55 -> 50 -> 45 -> 27 -> 40

Over 20,000 simulated cases with destitution modelled, phases passed roughly
double and destitution incidence roughly halves.

R-222: resolveLegDialog passed no skillFamilyId, so the choke point could not
resolve the skill item and leading a phase never earned a tick — Tradecraft, the
skill the job most uses, could never improve.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

rules.mjs

@@ -368,6 +368,35 @@ export function defencePenaltyFor(defencesUsed = 0) {
   return DEFENCE_STEP * Math.max(0, Number(defencesUsed) || 0);
 }
 
+/**
+ * HOW HARD A CASE PHASE IS.
+ *
+ * The old ramp made every phase after the first Difficult — which HALVES the lead's
+ * skill — and then stacked a cumulative −5% on top. Measured across two played
+ * cases, a realistic lead of 40–55% (Tradecraft is a support skill on most postings
+ * that train it at all) faced 20% → 15% → 10% → 5% → 1%, and both cases were decided
+ * by Resources running out rather than by anything the players did.
+ *
+ * The two pressures are now separated, because they were never the same idea:
+ *
+ *   DIFFICULTY is about the phase. Only Containment is Difficult — the step the case
+ *   is actually about — and it does not also take the ramp. It is hard because it is
+ *   containment, not because you are tired.
+ *
+ *   The MODIFIER is about attrition. It accumulates as the case wears on, and it
+ *   stops accumulating, because a fifth phase is not four times worse than a second.
+ */
+export const PHASE_RAMP = { step: -5, cap: -15, hardKinds: ["containment"] };
+
+export function phaseRampFor(index, kindId = "") {
+  const hard = PHASE_RAMP.hardKinds.includes(String(kindId));
+  return {
+    difficulty: hard ? "difficult" : "average",
+    // A hard phase carries its difficulty INSTEAD of the ramp, never both.
+    modifier: hard ? 0 : Math.max(PHASE_RAMP.cap, PHASE_RAMP.step * (Number(index) || 0))
+  };
+}
+
 /* -------------------------------------------- */
 /*  Borrowed Authority                          */
 /* -------------------------------------------- */