fix: remove the ClamAV virus scan (GH-28)

[mastacontrola]

Closes #28. Companion to fogproject#328 (FOGProject/fogproject#1608), which removes the task types, the clamav= kernel argument and the virus table server-side.

The scan cannot run today, on either release line

fog.av does not use a ClamAV built into the image — BR2_PACKAGE_CLAMAV is not set in both fsx64.config and fsarm64.config. It NFS-mounts the binaries from the server, at the path the clamav= argument carries: <server>:/opt/fog/clamav.

Neither installer has ever created or exported that directory. bin/installfog.sh and lib/ contain no reference to clamav on working-1.6 or on dev-branch, and the path is absent from a live 1.6 server's filesystem and its /etc/exports. The mount fails and the script dies at

handleError "Cannot find clamav binaries to run task."

before it reaches a single partition.

The reporting half is dead too

This is the part worth checking rather than assuming, because 1.5 looks live where 1.6 plainly is not.

1.6	never carried service/av.php across from 1.5 — nothing to post to
1.5	has the endpoint, the Virus model, the manager and the report — and rejects every submission

The 1.5 guard reads:

if (trim($_REQUEST['mode']) != array('q', 's')) {
    throw new Exception(_('Invalid operational mode'));
}

That compares a string to an array, and PHP ranks any array above any non-array — so it is true for every input and the endpoint always throws. Verified on 7.4.33 and 8.3.33, both supported; the line dates to 2014.

What this removes

• Buildroot/board/FOG/FOS/rootfs_overlay/bin/fog.av
• the clamav) arm of the mode dispatch in bin/fog
• the clamav) arm in bin/fog.checkin, which appended avmode to the check-in POST. Nothing reads it — avmode appears nowhere else in this tree, and neither Pre_Stage1.php nor mc_checkin.php references it on either branch
• fog.av from the documented raw-curl exceptions in tests/checks/server-post-reporting.sh

# BR2_PACKAGE_CLAMAV is not set stays in both configs. Those are generated defconfig lines present for every unselected package, not a choice this change gets to edit.

Behavior change, confined to 1.5

dev-branch still emits mode=clamav, so a 1.5 Virus Scan task now fails as Unknown mode :: clamav rather than Cannot find clamav binaries. Both are handleError paths reached before any scanning — no working behavior is lost. 1.6 stops emitting the mode entirely once fogproject#1608 lands.

Verified

• tests/run-all.sh — 18 passed, 0 failed, both before and after
• every touched script passes bash -n
• the exceptions trim restores a real gate, not just tidier text. Reintroducing a fog.av that reads a raw curl reply turns check 11 red:

  FAIL: 11. raw curl reads a reply only in the documented exceptions ( fog.av)
  passed: 14   failed: 1
  

  and green again once removed. Mutation run, not assumed.