feat(journal): var stuff

src/components/journal/var-reactivity.ts

@@ -22,7 +22,7 @@
  */
 
 import type { VarDeclaration, TagModifier } from "./declare-parser";
-import { evaluateExpression } from "./variable-expression";
+import { evaluateExpression, exprValueToString } from "./variable-expression";
 
 // ---------------------------------------------------------------------------
 // Types
@@ -349,7 +349,7 @@ export function computeInitialValues(
         },
       });
 
-      const rawValue = String(result.value);
+      const rawValue = exprValueToString(result.value);
       baseValues.set(key, rawValue);
 
       // Check if this is a tagmap value — if so, activate matching modifiers
@@ -422,7 +422,13 @@ function applyTagMapActivations(
             },
           });
 
-          const value = evalResult.value;
+          // Modifier expressions must evaluate to a number
+          if (evalResult.value.kind !== "number") {
+            throw new Error(
+              `Modifier expression "${mod.expression}" must evaluate to a number`,
+            );
+          }
+          const value = evalResult.value.value;
           const targetIsTagMap = isTagMapValue(baseValues.get(mod.target));
 
           if (targetIsTagMap) {
@@ -571,7 +577,7 @@ function reevaluateDependents(
         },
       });
 
-      const rawValue = String(result.value);
+      const rawValue = exprValueToString(result.value);
 
       // Check for tagmap transition on this declared variable
       const oldCombined = getCombined(key, fallback);