fix(impeccable): global-scope install with agents, pin fallback, output-read failure check

make plugin never installed impeccable. The 3.2.0 pin had rotted upstream
(the CLI fetches its skill dist at install time; that release's zip is
gone), the --scope=project staging moved the skill dir alone and dropped
the 4 impeccable-* subagents, and /impeccable init was never announced.

Step 8d now installs at --scope=global straight through the
~/.claude/{skills,agents} symlinks into the repo (both paths gitignored),
guards on those symlinks existing, keeps a profile-parked copy parked,
falls back to @latest on a pin failure with a bump-the-lock warning, and
prints the per-project init hint. update-all.sh mirrors the shape.

Found while probing: with a copy already installed a rotted pin exits 0
("Could not check for skill updates ... left unchanged"), byte-identical
on disk to an up-to-date rerun, so imp_install reads the installer output
instead of trusting the exit code. Harness 4/4 in a sandbox HOME with the
real installer.

plugins.lock.json: impeccable 3.2.0 -> 4.1.0 (CLI only). link.sh drops
impeccable from EXTERNAL_SKILLS. lib/design-gate.md section 5: suggest-only
/impeccable init check when a frontend project has no PRODUCT.md.

update-all.sh

@@ -379,11 +379,34 @@ else
   info "design-motion-principles not installed — skipping"
 fi
 
-# ── Impeccable (design anti-pattern detector + skill) ──
+# ── Impeccable (design detector + skill + subagents) ──
+# Global scope: the installer writes through the ~/.claude/{skills,agents}
+# symlinks straight into this repo (install-plugins.sh Step 8d explains why
+# staging + project scope was wrong). The pin can rot upstream, so a pinned
+# failure falls back to @latest rather than leaving the tool stale forever.
+#
+# One install attempt. $1 = "latest" or an exact version. On failure, IMP_FAIL
+# holds the reason. Same helper as Step 8d: with a copy already in place a
+# rotted pin exits 0 and says "Could not check for skill updates … left
+# unchanged", so the exit code cannot tell it from an up-to-date no-op.
+imp_install() {
+  local pkg="impeccable" out rc=0
+  [ "$1" != "latest" ] && pkg="impeccable@$1"
+  out=$(npx -y "$pkg" skills install -y --providers=claude --scope=global \
+    --no-hooks 2>&1) || rc=$?
+  IMP_FAIL=$(printf '%s\n' "$out" \
+    | grep -E 'Download failed|Could not check for skill updates' \
+    | head -1 || true)
+  if [ "$rc" -ne 0 ] && [ -z "$IMP_FAIL" ]; then
+    IMP_FAIL="installer exited $rc"
+  fi
+  [ -z "$IMP_FAIL" ]
+}
 echo ""
 echo "── Updating impeccable..."
-IMP_DIR="$REPO/skills-external/impeccable"
-if [ ! -f "$IMP_DIR/SKILL.md" ]; then
+IMP_SKILL_DIR="$HOME/.claude/skills/impeccable"
+IMP_PARKED="$REPO/skills-disabled/impeccable"
+if [ ! -f "$IMP_SKILL_DIR/SKILL.md" ] && [ ! -f "$IMP_PARKED/SKILL.md" ]; then
   info "impeccable not installed — skipping (run: make plugin)"
 else
   IMP_VER=""
@@ -397,26 +420,34 @@ print(d.get('impeccable',{}).get('version','latest'))
   fi
   IMP_NODE=$(node -v 2>/dev/null | sed 's/^v//' | cut -d. -f1)
   if [ -z "${IMP_NODE:-}" ] || [ "$IMP_NODE" -lt 24 ]; then
-    info "impeccable update skipped — needs Node >= 24 (found ${IMP_NODE:-none}); existing dist kept"
+    info "impeccable update skipped — needs Node >= 24 (found ${IMP_NODE:-none}); existing copy kept"
   else
-    IMP_PKG="impeccable"
-    # Pin honored (LRN-077 class: a silent rules update changes audit
-    # output on unchanged code) — bump the pin deliberately, then update.
-    [ -n "$IMP_VER" ] && [ "$IMP_VER" != "latest" ] && IMP_PKG="impeccable@${IMP_VER}"
-    IMP_STAGE=$(mktemp -d)
-    if (cd "$IMP_STAGE" && npx -y "$IMP_PKG" skills install -y --providers=claude --scope=project --no-hooks >/dev/null 2>&1); then
-      IMP_SRC=$(find "$IMP_STAGE" -type d -name impeccable -path "*skills*" 2>/dev/null | head -1)
-      if [ -n "$IMP_SRC" ] && [ -f "$IMP_SRC/SKILL.md" ]; then
-        rm -rf "$IMP_DIR"
-        mv "$IMP_SRC" "$IMP_DIR"
-        ok "impeccable refreshed (CLI ${IMP_VER:-latest})"
-      else
-        warn "impeccable: installer produced no dist — existing kept"
+    IMP_WAS_PARKED=false
+    [ -d "$IMP_PARKED" ] && IMP_WAS_PARKED=true
+    # Pin honored (LRN-077 class: a silent rules update changes audit output
+    # on unchanged code) — bump the pin deliberately, then update.
+    IMP_PIN="${IMP_VER:-latest}"
+    IMP_OK=false
+    if imp_install "$IMP_PIN"; then
+      IMP_OK=true
+    elif [ "$IMP_PIN" != "latest" ]; then
+      warn "impeccable@${IMP_PIN} did not install (${IMP_FAIL}) — that release's skill dist is gone upstream; trying @latest"
+      if imp_install latest; then
+        IMP_OK=true
+        warn "refreshed from @latest, not the pin — bump \"impeccable\".version in plugins.lock.json"
+      fi
+    fi
+    if [ "$IMP_OK" = true ] && [ -f "$IMP_SKILL_DIR/SKILL.md" ]; then
+      IMP_SKILL_VER=$(sed -n 's/^version:[[:space:]]*//p' "$IMP_SKILL_DIR/SKILL.md" | head -1)
+      ok "impeccable refreshed (CLI ${IMP_VER:-latest}, skill ${IMP_SKILL_VER:-?})"
+      if [ "$IMP_WAS_PARKED" = true ]; then
+        rm -rf "${IMP_PARKED:?}"
+        mv "$IMP_SKILL_DIR" "$IMP_PARKED"
+        info "impeccable was parked by a profile — refreshed copy returned to skills-disabled/"
       fi
     else
-      warn "impeccable refresh failed — existing dist kept"
+      warn "impeccable refresh failed (${IMP_FAIL:-no SKILL.md written}) — existing copy kept"
     fi
-    rm -rf "$IMP_STAGE"
   fi
 fi