fix(test): isolate real-world usage tests with explicit spy clearing

Add mockClear() calls at the start of "progress indicator pattern" and
"table rendering" tests to ensure they run with clean spy state. These
tests check absolute call counts and were accumulating calls from
previous tests in the describe block on Node.js 24.

Author: jdalton

test/stdio/stdout.test.ts

@@ -528,6 +528,8 @@ describe('stdio/stdout', () => {
         value: true,
         configurable: true,
       })
+      // Clear spy to ensure this test runs in isolation
+      getContext().writeSpy.mockClear()
       write('Loading...')
       clearLine()
       write('Loading... 50%')
@@ -555,6 +557,8 @@ describe('stdio/stdout', () => {
     })
 
     it('should support table rendering', () => {
+      // Clear spy to ensure this test runs in isolation
+      getContext().writeSpy.mockClear()
       writeLine('Name        | Age | City')
       writeLine('------------|-----|-------')
       writeLine('John Doe    | 30  | NYC')