fix: harden local installation guide

scripts/test-verify-workspace-install-docs.sh

@@ -4,7 +4,9 @@ set -euo pipefail
 
 root="$(cd "$(dirname "$0")/.." && pwd -P)"
 output="$(mktemp "${TMPDIR:-/tmp}/thoth-install-docs-test.XXXXXX")"
-trap 'rm -f "$output"' EXIT HUP INT TERM
+verifier_functions="$(mktemp "${TMPDIR:-/tmp}/thoth-install-docs-functions.XXXXXX")"
+negative_root="$(mktemp -d "${TMPDIR:-/tmp}/thoth-install-docs-negative.XXXXXX")"
+trap 'rm -f "$output" "$verifier_functions"; rm -rf "$negative_root"' EXIT HUP INT TERM
 
 "$root/scripts/verify-workspace-install-docs.sh" --fixtures-only >"$output"
 
@@ -17,7 +19,8 @@ for fixture in \
   "server manual canonical base+override references" \
   "canonical local base+override fixture" \
   "canonical server base+override fixture" \
-  "relative secret-source fixture rejected"; do
+  "relative secret-source fixture rejected" \
+  "CRLF recovery rewrites worktree bytes"; do
   grep -Fqx "$fixture passed" "$output" >/dev/null || {
     echo "missing fixture verification: $fixture" >&2
     cat "$output" >&2
@@ -48,3 +51,87 @@ if rg -n 'local-compose\.workspace-registry|server-compose\.workspace-registry|c
   echo "installation manuals still document a bypassed Compose or copied connector override path" >&2
   exit 1
 fi
+
+# Load only the verifier's function definitions so each deliberately unsafe guide can be checked
+# in isolation without invoking Docker-backed Compose fixtures.
+sed '/^case "\$mode" in/,$d' "$root/scripts/verify-workspace-install-docs.sh" >"$verifier_functions"
+# shellcheck source=/dev/null
+source "$verifier_functions"
+
+negative_failures=0
+expect_guide_rejected() {
+  local label="$1" validator="$2" source_guide="$3" relative_path="$4"
+  local mutation="$5" expected_error="$6"
+  local fixture_root="$negative_root/${label// /-}"
+  local fixture_output="$fixture_root/output"
+  mkdir -p "$fixture_root/$(dirname "$relative_path")"
+  cp "$source_guide" "$fixture_root/$relative_path"
+  node - "$fixture_root/$relative_path" "$mutation" <<'NODE'
+const fs = require("fs");
+const [path, mutation] = process.argv.slice(2);
+const original = fs.readFileSync(path, "utf8");
+let changed = original;
+switch (mutation) {
+  case "durable-selector":
+    changed = original.replaceAll("--source build", "--source stale-build");
+    break;
+  case "dangerous-volumes":
+    changed = original.replace("Do **not** run `docker compose down --volumes`", "Run `docker compose down --volumes`");
+    break;
+  case "incomplete-powershell":
+    changed = original.replaceAll("icacls.exe", "Write-Output");
+    break;
+  case "broken-crlf":
+    changed = original.replaceAll("git checkout-index --all --force --prefix=", "git add --renormalize . # ");
+    break;
+  case "raw-pi":
+    changed += "\n```sh\ndocker compose exec core pi --version\n```\n";
+    break;
+  default:
+    throw new Error(`unknown negative-fixture mutation: ${mutation}`);
+}
+if (changed === original) throw new Error(`negative-fixture mutation made no change: ${mutation}`);
+fs.writeFileSync(path, changed);
+NODE
+  set +e
+  (root="$fixture_root"; set -e; "$validator") >"$fixture_output" 2>&1
+  local status=$?
+  set -e
+  if [[ $status -eq 0 ]]; then
+    echo "negative fixture accepted: $label" >&2
+    cat "$fixture_output" >&2
+    negative_failures=$((negative_failures + 1))
+  elif ! grep -Fq -- "$expected_error" "$fixture_output"; then
+    echo "negative fixture failed for the wrong reason: $label" >&2
+    cat "$fixture_output" >&2
+    negative_failures=$((negative_failures + 1))
+  fi
+}
+
+expect_guide_rejected \
+  "durable selector keeps old core" verify_local_guide \
+  "$root/docs/install/local.md" docs/install/local.md durable-selector \
+  "installation-aware source update lacks structural token: --source build"
+expect_guide_rejected \
+  "dangerous down volumes instruction" verify_local_guide \
+  "$root/docs/install/local.md" docs/install/local.md dangerous-volumes \
+  "docker compose down --volumes must appear only in an explicit prose prohibition"
+expect_guide_rejected \
+  "incomplete native PowerShell path" verify_local_guide \
+  "$root/docs/install/local.md" docs/install/local.md incomplete-powershell \
+  "native PowerShell setup lacks structural token: icacls.exe"
+expect_guide_rejected \
+  "renormalize leaves CRLF worktree bytes" verify_windows_line_endings_guide \
+  "$root/docs/install/windows-line-endings.md" docs/install/windows-line-endings.md broken-crlf \
+  "Windows line-ending guide lacks required instruction: git checkout-index --all --force"
+expect_guide_rejected \
+  "raw non-installation-aware Pi access" verify_pi_management_guide \
+  "$root/docs/install/pi-management.md" docs/install/pi-management.md raw-pi \
+  "raw non-installation-aware Compose Pi access is forbidden"
+
+if (( negative_failures != 0 )); then
+  echo "$negative_failures unsafe installation-document fixtures were accepted" >&2
+  exit 1
+fi
+
+echo "unsafe installation-document fixtures rejected passed"