hub: delete the host-install version label (R-94) + invert hostinstall gate 1

The Setup tab said 'host-install 1.19.0' while the served script was 1.22.0, and had
been wrong since 2026-07-14. Deriving the number honestly is not possible: the Option-1
command downloads felhom-host-install.sh from the website at RUN TIME and the website
git-syncs main every 30s (R-110), so no build-time value in the hub can be true. R-94(a)
offered derive-or-delete; deleted, which removes the drift class instead of automating it.

- configs.go: hostInstallVersion const, pageData.ScriptVersion field and its assignment
  all removed; a NOTE in their place records why there is no constant here.
- customer_unified.html: the sentence now says the command always fetches the current
  installer, and renders no version.
- hostinstall_gates.py gate 1: the third assertion INVERTS — it used to require the hub
  const to equal SCRIPT_VERSION, it now asserts the hub carries no host-install version
  literal at all, matched in six code shapes across every .go/.html under hub/ (comments
  are deliberately not stripped: a // inside a URL literal would blind the scan).
- render_test.go: the assertion 'html contains hostInstallVersion' compared the constant
  to itself and passed at ANY value — demonstrated green with the const at 9.9.9 while the
  script was 1.22.0. Deleted, not replaced: there is no longer a version to assert.
- felhom-host-install.sh: COMMENT ONLY (SCRIPT_VERSION untouched) — it claimed the gate
  keeps the hub copy equal, an invariant that no longer exists.

Red-proofs: restoring the const fails the rewritten gate 1 (3 shapes hit); the old
render_test assertion passes at 9.9.9.

hub/internal/web/render_test.go

@@ -215,10 +215,11 @@ func TestTemplates_InstallGenerator(t *testing.T) {
 			t.Errorf("generator control missing: %s", id)
 		}
 	}
-	// targets the right script version + carries the client-side customer id
-	if !strings.Contains(html, hostInstallVersion) {
-		t.Errorf("ScriptVersion %s not rendered", hostInstallVersion)
-	}
+	// carries the client-side customer id. There is deliberately NO version assertion here: R-94
+	// deleted the rendered host-install version, because the hub cannot know which version a box
+	// will run (the script is fetched at run time). The assertion that used to sit here compared
+	// hostInstallVersion to itself and passed at any value — it was demonstrated green with the
+	// const set to "9.9.9" while the served script was 1.22.0.
 	if !strings.Contains(html, `data-customer-id="peti-felhom"`) {
 		t.Errorf("generator missing data-customer-id")
 	}