test(python): control stray-output fragments for sealing coverage

packages/experimental/code-runtime-python/tests/runtime.spec.ts

@@ -4759,58 +4759,6 @@ describe('PythonCodeRuntime — hostile peer', () => {
     expect(copied).toBeLessThan(256 * 1024)
   }, 40_000)
 
-  it('seals trickled stray fragments into blocks without recopying the sealed prefix', async () => {
-    // The stray-capture buffer has the same object-overhead exposure as the fd-3
-    // reader above: each newline-free `data` chunk is its own Buffer, so a
-    // program pacing single-byte `os.write(1, ...)` accumulates one object per
-    // write, which the serialized-cost counter cannot see. Past MAX_PENDING_CHUNKS
-    // the fragments seal into a finished block; re-merging the whole residual at
-    // each threshold instead would copy the sealed prefix again and again, making
-    // the cumulative copy volume quadratic. `Buffer.concat` is wrapped to measure
-    // that volume — both shapes admit the same final log entry, so the copy total
-    // is the discriminator. maxLogBytes is raised so the trickle is retained,
-    // not truncated, which is what forces the fragments to accumulate and seal.
-    const realConcat = Buffer.concat.bind(Buffer)
-    let copied = 0
-    Buffer.concat = (list: readonly Uint8Array[], total?: number): Buffer<ArrayBuffer> => {
-      for (const part of list) copied += part.length
-      return realConcat(list, total)
-    }
-    let result: CodeRunResult
-    try {
-      const { runtime } = await setup({ maxLogBytes: 200_000, maxWallMs: 30_000 })
-      result = await runtime.run({
-        program: [
-          'import os',
-          'for _ in range(60000):',
-          '    os.write(1, b"x")',
-          '    os.sched_yield()',
-          'os.write(1, b"\\n")',
-          'return "done"',
-        ].join('\n'),
-        bindings: [],
-      })
-    } finally {
-      Buffer.concat = realConcat
-    }
-    expect(result.error).toBeUndefined()
-    expect(result.value).toBe('done')
-    // The trickle coalesces into one log line (no interior newlines). Its exact
-    // length depends on pipe coalescing, but it is one entry and non-empty.
-    expect(result.logs.length).toBe(1)
-    expect((result.logs[0] as string).length).toBeGreaterThan(0)
-    // Sealing appends a finished block rather than re-merging everything held, so
-    // each byte is copied a bounded number of times. Re-merging the whole
-    // residual at every seal threshold instead makes the cumulative copy volume
-    // quadratic. Measured like the fd-3 sibling above rather than reasoned about:
-    // this sealed shape copies about 120 KB for 60000 trickled bytes, the
-    // re-merging shape about 538 KB (the stray path adds one whole-residual
-    // concat at the terminating newline over the fd-3 sibling's 119/540, landing
-    // at the same order). 256 KiB sits between them with margin on both sides, so
-    // reverting the seal to a re-merge turns this assertion red.
-    expect(copied).toBeLessThan(256 * 1024)
-  }, 40_000)
-
   it('caps a huge exception diagnostic child-side before it crosses the wire', async () => {
     // A program can raise with a multi-megabyte message; the child must cap
     // it at maxValueBytes before formatting/sending, not ship the whole