feat(journal): seed declared variables on initialization

Implement `computeInitialValues` to calculate the starting state of
declared variables and seed them into the journal stream store during
the completions initialization process.

src/components/journal/completions.ts

@@ -25,7 +25,8 @@ import {
 } from "../../cli/completions/directive-scanner";
 import { parseDeclareCsv } from "./declare-parser";
 import type { VarDeclaration, TagModifier } from "./declare-parser";
-import { initReactivity } from "./var-reactivity";
+import { initReactivity, computeInitialValues } from "./var-reactivity";
+import { sendMessage, journalStreamState } from "../stores/journalStream";
 
 export type { VarDeclaration, TagModifier };
 
@@ -171,7 +172,10 @@ const _initPromise: Promise<void> = (async () => {
   const serverData = await tryServer();
   if (serverData) {
     setCompletionsState({ status: "loaded", data: serverData });
-    try { initReactivity({ declarations: serverData.declarations, tagModifiers: serverData.tagModifiers }); } catch (e) { console.warn("[completions] reactivity init error:", e); }
+    try {
+      initReactivity({ declarations: serverData.declarations, tagModifiers: serverData.tagModifiers });
+      seedDeclaredVariables();
+    } catch (e) { console.warn("[completions] reactivity init error:", e); }
     return;
   }
 
@@ -180,7 +184,10 @@ const _initPromise: Promise<void> = (async () => {
     const data = await scanClientSide();
     if (data.dice.length > 0 || data.links.length > 0) {
       setCompletionsState({ status: "loaded", data });
-      try { initReactivity({ declarations: data.declarations, tagModifiers: data.tagModifiers }); } catch (e) { console.warn("[completions] reactivity init error:", e); }
+      try {
+        initReactivity({ declarations: data.declarations, tagModifiers: data.tagModifiers });
+        seedDeclaredVariables();
+      } catch (e) { console.warn("[completions] reactivity init error:", e); }
     } else {
       setCompletionsState({ status: "empty" });
     }
@@ -230,4 +237,15 @@ export function useJournalCompletions(): {
       tagModifiers: [],
     },
   };
+}
+
+// ---------------------------------------------------------------------------
+// Seed declared variables into the store on load
+// ---------------------------------------------------------------------------
+
+function seedDeclaredVariables(): void {
+  const initial = computeInitialValues(journalStreamState.variables);
+  for (const { key, value } of initial) {
+    sendMessage("var", { action: "set", key, value });
+  }
 }