docs: correct the check count and mirror the statusctl hardening

Two corrections to the plan, both found by running it rather than reading
it.

The test script the plan specifies makes nine assertions; the prose around
it claimed eight, in both the task step and the final check. An implementer
running it would see a passing suite that disagrees with its own expected
output, which reads as a failure of either the test or the plan. My
arithmetic.

The plan's statusctl also swallowed a failed rename and read the mode file
through cat piped into tr, so a write that did not land still reported
success and an unreadable file fell back to off by accident of pipeline
semantics rather than by intent. Review of the implemented script caught
both. The plan now carries the same fixes, so a future run of it does not
reintroduce them.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01A7ThHHh5iTYbVfp3rNAkw2

1 files changed, 13 insertions, 4 deletions

diff --git a/docs/superpowers/plans/2026-09-15-status-registry.md b/docs/superpowers/plans/2026-09-15-status-registry.md
index 3b95743..5f86de4 100644
--- a/docs/superpowers/plans/2026-09-15-status-registry.md
+++ b/docs/superpowers/plans/2026-09-15-status-registry.md
@@ -391,7 +391,11 @@ file="$DIR/status.$mode"
 
 read_mode() {
     local v
-    v="$(cat "$file" 2>/dev/null | tr -d '[:space:]')"
+    # An unreadable file reads as off, deliberately: a missing mode file is
+    # the normal state before anything has written one, and the redirect
+    # makes that fallback explicit rather than a side effect of a pipeline
+    # swallowing cat's exit status.
+    v="$(tr -d '[:space:]' < "$file" 2>/dev/null)"
     [[ "$v" == "1" ]] && printf '1' || printf '0'
 }
 
@@ -402,7 +406,12 @@ write_mode() {
     local want="$1" tmp
     tmp="$(mktemp "$DIR/.status.$mode.XXXXXX")" || exit 1
     printf '%s\n' "$want" > "$tmp"
-    mv -f "$tmp" "$file"
+    # The temp file is made in the same directory as the target, so this is a
+    # rename rather than a copy, and therefore atomic. A failure here has to
+    # be loud: reporting success on a write that did not land would leave the
+    # caller and the shell disagreeing about the mode, with an orphan temp
+    # file as the only trace.
+    mv -f "$tmp" "$file" || { rm -f "$tmp"; exit 1; }
 }
 
 emit() {
@@ -464,7 +473,7 @@ chmod +x desktop/modules/status/statusctl
 bash desktop/modules/status/test-statusctl.sh
 ```
 
-Expected: `8 passed, 0 failed`, exit 0.
+Expected: `9 passed, 0 failed`, exit 0.
 
 - [ ] **Step 5: Commit**
 
@@ -1184,7 +1193,7 @@ bash desktop/modules/kdeconnect/test-kdeconnect-state.sh
 timeout 8 qs -p ./desktop 2>&1 | grep -E 'ERROR|TypeError|ReferenceError|is not defined|Cannot assign|Unable to assign' && echo "ERRORS ABOVE" || echo "clean"
 ```
 
-Expected: statusctl `8 passed, 0 failed`; mail 16 of 16; kdeconnect 5 of 5; `clean`.
+Expected: statusctl `9 passed, 0 failed`; mail 16 of 16; kdeconnect 5 of 5; `clean`.
 
 - [ ] **Step 4: Confirm the process count**