Add a CompoundCurve to (ramp, add) helper with a boot check

FlatLine -> (0, add), SlopedLine p -> (p, add), SlopedInitValLine p ->
(p, no add), checked against every static_power_effectmod and
static_power_action row (6228 rows; the 11 ramp value diffs are the
known 4.0 effectmod diffs). DefaultCurveUp/Down have no ramp form and
no mod or action uses them. The world boot checks five known DB rows
and logs curves without a ramp form.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/engine/server/world/WorldServer.java

@@ -41,6 +41,7 @@ import engine.parsers.objects.ItemTemplate;
 import engine.parsers.objects.RuneTemplate;
 import engine.parsers.objects.wpak.CharCreateRuneList;
 import engine.parsers.objects.wpak.CompoundCurveTemplate;
+import engine.parsers.objects.wpak.CurveRamp;
 import engine.parsers.objects.wpak.EffectTemplate;
 import engine.parsers.objects.wpak.ModTypeTemplate;
 import engine.parsers.objects.wpak.PowActionCostTemplate;
@@ -306,6 +307,8 @@ public class WorldServer {
             exit(1);
         }
 
+        CurveRamp.verifyRampForms();
+
         Logger.info("Loading Mod Types");
         ModTypeTemplate._modTypes = ModTypeParser.parseModTypesFile();