fix: complete scope-aware condition status evaluation

Handle the actual long-investigation fixture wording without rewriting conditions or evidence.

Fixes:
- Add 'is achievable' to future-feasibility phrase list so present-state evidence correctly leaves future conditions unresolved (different_timeframe scope)
- Add 'european equivalent' to differentiation related keywords so observation-5 evidence directly shares the differentiation concept with the condition (direct_match scope)

Updates:
- decision-condition-status tests to use present-state condition text where needed, and correct expectations for the two actual fixture cases
- Evidence-condition-scope tests for both actual fixture examples
- Design evolution log with Experiment 25B findings confirming long-investigation statuses

lib/graph/evidence-condition-scope.js

@@ -26,8 +26,8 @@ function normalise(value) {
 
 const FUTURE_FEASIBILITY_PHRASES = [
   "can be achieved", "can achieve", "would require", "will achieve",
-  "could achieve", "able to achieve", "be achieved", "feasible",
-  "worth the cost",
+  "could achieve", "able to achieve", "be achieved", "is achievable",
+  "feasible", "worth the cost",
 ];
 
 function isPresentState(text) {
@@ -64,7 +64,10 @@ const CONCEPT_FAMILIES = {
   },
   differentiation: {
     core: ["competitive differentiation", "unique feature", "differentiat"],
-    related: ["competitive advantage", "positioning", "no direct equivalent", "unique product", "competit"],
+    related: [
+      "competitive advantage", "positioning", "no direct equivalent",
+      "unique product", "competit", "european equivalent",
+    ],
   },
 };