fix: detached array buffer on memory growth (#17859)

Caused issues with boxes:

<img width="479" height="182" alt="image"
src="https://github.com/user-attachments/assets/74f687c4-7cad-4b53-8108-91216adee2e2"
/>

References for the fix:
-
https://awesome.red-badger.com/chriswhealy/memory-grow-and-arraybuffers
-
https://stackoverflow.com/questions/51659292/javascript-arraybuffer-detaches-when-constructing-a-new-rust-vec-via-wasm

Author: Thunkar

barretenberg/ts/src/barretenberg_wasm/barretenberg_wasm_main/index.ts

@@ -173,9 +173,9 @@ export class BarretenbergWasmMain extends BarretenbergWasmBase {
     const scratchDataPtr = this.msgpackOutputScratch + METADATA_SIZE;
     const scratchDataSize = this.MSGPACK_SCRATCH_SIZE - METADATA_SIZE;
 
-    // Get memory once and create DataView for all reads/writes (avoids creating multiple typed arrays)
-    const mem = this.getMemory();
-    const view = new DataView(mem.buffer);
+    // Get memory and create DataView for writing IN values
+    let mem = this.getMemory();
+    let view = new DataView(mem.buffer);
 
     // Write IN values: provide scratch buffer pointer and size to C++
     view.setUint32(outputPtrLocation, scratchDataPtr, true);
@@ -189,6 +189,10 @@ export class BarretenbergWasmMain extends BarretenbergWasmBase {
       this.call('bbfree', inputPtr);
     }
 
+    // Re-fetch memory after WASM call, as the buffer may have been detached if memory grew
+    mem = this.getMemory();
+    view = new DataView(mem.buffer);
+
     // Read OUT values: C++ returns actual buffer pointer and size
     const outputDataPtr = view.getUint32(outputPtrLocation, true);
     const outputSize = view.getUint32(outputSizeLocation, true);