[DevomB]

The third part of the cleanup-held redo (after #241 and #242). These are comments only, in tools/image/install-test.sh, state-test.sh, update-test.sh, suite-lib.sh and vm-drive.py.

How it was done. The same procedure as #242. Cleanup-held's change was merged onto main, and only regions where every changed line is a comment or blank were kept. Code, messages and every conflict went back to main, and each kept cut was then read by hand. Stripping comments from main's version and this one gives the same code in all five files; bash -n passes and vm-drive.py parses.

Taken where the cut corrects main: suite-lib's header now says what install_disk reads (TIMEOUT, VMDIR).

Changed from the cut, to keep a reason it dropped:

• update-test's header keeps the broken trial among what it covers.
• Its channel comment keeps what the not-a-pointer control is: the statement signed in the manifest's namespace, which only a development build makes.
• suite-lib keeps that the production pair signs its control disks with its own testctl key.

Gone with the cut, checked against the code:

• update-test's "plain http is for development images only": the suite writes an http channel (channel = http://10.0.2.2:…) on either role, so it was untrue there.
• The comment above the request-order check: its own pass and fail lines state the same order.

Proof: CI (shellcheck, syntax). These suites run only in the Distro workflow, and nothing they do changes; no file outside these five is touched.