R-733 red-proof: venue_swap_bytes returns None always; swap_peak_of ignores the kernel's swap_peak
test_kernel_peak_counts (__main__.SwapRecorded.test_kernel_peak_counts) ... FAIL
test_venue_swap_read (__main__.SwapRecorded.test_venue_swap_read) ... FAIL
FAIL: test_kernel_peak_counts (__main__.SwapRecorded.test_kernel_peak_counts)
    self.assertEqual(ut.swap_peak_of(samples, "app", {"swap": 5, "swap_peak": 99}), 99)
AssertionError: 30 != 99
FAIL: test_venue_swap_read (__main__.SwapRecorded.test_venue_swap_read)
    self.assertEqual(ut.venue_swap_bytes("MemTotal:  1 kB\nSwapTotal:       524288 kB\nSwapFree: 1 kB\n"), 512 * 2**20)
AssertionError: None != 536870912
Ran 4 tests in 0.002s
FAILED (failures=2)

Positive observable, read 2026-10-06 ~21:15 CEST: the bench 9401 reads `SwapTotal: 0 kB`, scratch 9202 reads
`SwapTotal: 524288 kB` (both via pct exec on demo-hp, kernel 7.0.14-20-pve); the cgroup v2 root on the bench has
memory.swap.current and memory.swap.peak, the files the snapshot now reads.
