feat: enhance canvas functionality with proximity edge handling and improved authentication logging

- Introduced temporary edge styling for proximity connections in the canvas.
- Updated edge synchronization logic to filter out temporary edges during data processing.
- Enhanced authentication logging to provide detailed user identity information when authentication fails.
- Added a new utility function for sanitizing edge handle IDs to ensure compatibility with React Flow.
- Implemented a node handle mapping for proximity connections to streamline edge management.

convex/helpers.ts

@@ -17,7 +17,12 @@ export async function requireAuth(
 ): Promise<AuthUser> {
   const user = await authComponent.safeGetAuthUser(ctx);
   if (!user) {
-    console.error("[requireAuth] safeGetAuthUser returned null");
+    const identity = await ctx.auth.getUserIdentity();
+    console.error("[requireAuth] safeGetAuthUser returned null", {
+      hasIdentity: Boolean(identity),
+      identityIssuer: identity?.issuer ?? null,
+      identitySubject: identity?.subject ?? null,
+    });
     throw new Error("Unauthenticated");
   }
   const userId = user.userId ?? String(user._id);