fix(executor): divide after a postfix update

`+` and `-` precede a regex as operators, but doubled they end a value, so
`i++ / 2` was scanning a regex from the division and swallowing whatever
quotes followed it on that line. The check now reads the pair rather than
the single character; a lone `+` still admits `params.n + /re/.test(x)`.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: icecrasher321

apps/sim/executor/variables/resolver.test.ts

@@ -1000,6 +1000,27 @@ describe('VariableResolver function block inputs', () => {
     expect(code).toContain(`Number('' + JSON.stringify(globalThis["__blockRef_2"]) + '')`)
   })
 
+  it('divides after a postfix update rather than opening a regex', async () => {
+    const { block, ctx, resolver } = createResolver('javascript')
+
+    const result = await resolver.resolveInputsForFunctionBlock(
+      ctx,
+      'function',
+      {
+        code: [
+          `let i = params.i; const half = i++ / 2 + Number('<producer.result>')`,
+          // The same characters as an operator still precede a regex.
+          `const hit = params.n + /['"]/.test('<producer.result>')`,
+        ].join('\n'),
+      },
+      block
+    )
+
+    const code = result.resolvedInputs.code as string
+    expect(code).toContain(`Number('' + JSON.stringify(globalThis["__blockRef_0"]) + '')`)
+    expect(code).toContain(`.test('' + JSON.stringify(globalThis["__blockRef_1"]) + '')`)
+  })
+
   it('does not read a method named after a keyword as a control-flow head', async () => {
     const { block, ctx, resolver } = createResolver('javascript')
 

apps/sim/executor/variables/resolver.ts

@@ -1165,6 +1165,13 @@ export class VariableResolver {
     if (previous === '/' && closes.regexCloseIndices.has(previousSignificantIndex)) {
       return false
     }
+    // `+` and `-` precede a regex as operators but end a value when doubled: `i++ / 2` divides.
+    if (
+      (previous === '+' || previous === '-') &&
+      template[previousSignificantIndex - 1] === previous
+    ) {
+      return false
+    }
     if (JAVASCRIPT_REGEX_ALLOWED_AFTER.has(previous)) {
       return true
     }