fix(occt): treat a broken wasm function table as a dead heap

src/kernel/backends/occt/occtException.test.ts

@@ -115,6 +115,13 @@ describe('isOcctWasmPoisoned', () => {
     expect(isOcctWasmPoisoned(err)).toBe(true);
   });
 
+  it('recognizes a broken wasm function table', () => {
+    const err = new Error('null function or function signature mismatch');
+    err.name = 'RuntimeError';
+    expect(isOcctWasmPoisoned(err)).toBe(true);
+    expect(isOcctWasmPoisoned(new Error('RuntimeError: null function or function signature mismatch'))).toBe(true);
+  });
+
   it('recognizes worker-wrapped Error messages', () => {
     expect(isOcctWasmPoisoned(new Error('RuntimeError: memory access out of bounds'))).toBe(true);
   });

src/modeling/compute/recomputeEngine.ts

@@ -594,24 +594,12 @@ export class RecomputeEngine {
         return await this.runPass(records, opts);
       } catch (retryErr) {
         if (!isOcctWasmPoisoned(retryErr)) throw retryErr;
-        const message =
+        // Throw, do not return a per-feature diagnostic. A returned failure
+        // leaves this dead heap in service and the viewer never gets a mesh.
+        throw new Error(
           `${WASM_POISON_MARKER}: ${describeOcctThrow(retryErr)}. ` +
-          'OCCT was reset and the full recompute retried; still failing. Restart the host process.';
-        return {
-          shapes: new Map(),
-          diagnostics: [{
-            target: this.lowerer.target,
-            code: 'recompute.lowering.exception',
-            severity: 'error',
-            message,
-            hint:
-              'The OCCT wasm heap was corrupted (often by an embind double-free). ' +
-              'Reset + retry did not recover; restart the Node/export process or reload Studio.',
-          }],
-          health: new Map(),
-          mechanism: 'unverified',
-          mechanismFailures: [],
-        };
+          'OCCT was reset and the full recompute retried; still failing. Restart the host process.',
+        );
       }
     }
   }

src/shared/occt/wasmPoison.ts

@@ -19,6 +19,11 @@ function looksLikeWasmPoisonText(text: string): boolean {
   // Emscripten abort() after unrecoverable wasm failure (truncated BREP, etc.).
   if (t.includes('aborted()') || t.includes('aborted(')) return true;
   if (t.includes('runtimeerror') && t.includes('aborted')) return true;
+  // Function-table corruption. Prod OCCT workers threw
+  // "RuntimeError: null function or function signature mismatch" and every
+  // later feature was recorded as a normal compile failure, so the worker
+  // stayed up and the viewer never painted.
+  if (t.includes('function signature mismatch') || t.includes('null function')) return true;
   return false;
 }