fix(newos4): the audit stops inventing '999d unused' (v4.6.85)

getStaleSkills() returned daysUnused=999 for a skill that had useCount 0 and no lastUsed — a
placeholder rendered by the audit as '999d unused', indistinguishable from a measurement. It told
the operator to archive procedural memory that had simply never been instrumented.

Now: daysUnused null + neverUsed true when there is no lastUsed; real day count otherwise; the
audit prints '(never used)'.

Verified: probe skill with no telemetry -> {daysUnused: null, neverUsed: true}; one last used
2026-08-01 -> 83; no 999 anywhere in getStaleSkills() or the audit output.

6 files changed, 32 insertions, 9 deletions

diff --git a/help.html b/help.html
index 5bf3543..9b39849 100644
--- a/help.html
+++ b/help.html
@@ -1689,6 +1689,21 @@ listmods</pre>
     <h2>📋 Changelog</h2>
 
     <div class="version-item">
+      <div class="v-header"><span class="v-num">v4.6.85 — October 2026</span>
+        <span class="v-date">no invented numbers</span></div>
+      <ul>
+        <li><strong>"999d unused" was a placeholder, printed as if measured.</strong> A skill with no
+          usage telemetry got <code>daysUnused = 999</code>, so the audit listed it as unused for
+          nearly three years — a fabricated figure that invited archiving good skills. It now
+          separates the two real cases: <code>(never used)</code> when there is no
+          <code>lastUsed</code> at all, and a genuine day count otherwise.</li>
+        <li><strong>The audit already distinguished untracked skills.</strong> 24 skills with no
+          telemetry are reported as <em>untracked</em>, not stale — the sentinel was the one place
+          that still pretended to know.</li>
+      </ul>
+    </div>
+
+    <div class="version-item">
       <div class="v-header"><span class="v-num">v4.6.83–84 — October 2026</span>
         <span class="v-date">world_model_query</span></div>
       <ul>
diff --git a/main.html b/main.html
index 41a7c82..a8586ce 100644
--- a/main.html
+++ b/main.html
@@ -1349,13 +1349,13 @@
     </script>
 
     <!-- v4.5.63: A2A scratchpad fixes + agent-register arg fix -->
-<script src="modules/core/core-bundle.js?v=v4.6.84"></script>
+<script src="modules/core/core-bundle.js?v=v4.6.85"></script>
 
     <!-- Async dependency-ordered module loader now only initializes terminal and loads optional ext modules -->
-<script src="modules/core/module-loader.js?v=v4.6.84"></script>
+<script src="modules/core/module-loader.js?v=v4.6.85"></script>
 
     <!-- Critical ext bundle loads AFTER webx11 exists so registerModule calls work -->
-<script src="modules/ext/critical-ext-bundle.js?v=v4.6.84"></script>
+<script src="modules/ext/critical-ext-bundle.js?v=v4.6.85"></script>
 
 <script>
 // ═══ ONE TRUE VERSION SOURCE ═══
diff --git a/modules/core/core-bundle.js b/modules/core/core-bundle.js
index 0b2795a..c8a4c2e 100644
--- a/modules/core/core-bundle.js
+++ b/modules/core/core-bundle.js
@@ -17912,8 +17912,11 @@ class MemoryGraphModule {
                 var useCount = stats.useCount || 0;
                 var lastUsed = stats.lastUsed ? new Date(stats.lastUsed).getTime() : 0;
                 if (useCount === 0 && (now - lastUsed > staleThreshold || lastUsed === 0)) {
-                    var daysUnused = lastUsed > 0 ? Math.floor((now - lastUsed) / 86400000) : 999;
-                    stale.push({ name: name, daysUnused: daysUnused });
+                    // v4.6.85: never fabricate a measurement. A skill with useCount 0 and no
+                    // lastUsed has NEVER been used — reporting it as "999d unused" invented a
+                    // number that then appeared in the audit as if it had been observed.
+                    var daysUnused = lastUsed > 0 ? Math.floor((now - lastUsed) / 86400000) : null;
+                    stale.push({ name: name, daysUnused: daysUnused, neverUsed: lastUsed === 0 });
                 }
             }
             this._untrackedSkills = untracked;
diff --git a/modules/core/module-loader.js b/modules/core/module-loader.js
index 9a373a6..1b0f6d9 100644
--- a/modules/core/module-loader.js
+++ b/modules/core/module-loader.js
@@ -4,7 +4,7 @@
     // Core module bundle loaded synchronously in main.html.
     // This loader only handles version cache-busting, splash, terminal init, and optional ext modules.
 
-    const LATEST_VER = 'v4.6.84';
+    const LATEST_VER = 'v4.6.85';
     const CACHE = '?v=' + LATEST_VER;
     const stored = localStorage.getItem('webx11_cache_ver');
     if (stored !== LATEST_VER) {
diff --git a/modules/core/module-memory-graph.js b/modules/core/module-memory-graph.js
index 093d2e4..1cb0919 100644
--- a/modules/core/module-memory-graph.js
+++ b/modules/core/module-memory-graph.js
@@ -482,8 +482,11 @@ class MemoryGraphModule {
                 var useCount = stats.useCount || 0;
                 var lastUsed = stats.lastUsed ? new Date(stats.lastUsed).getTime() : 0;
                 if (useCount === 0 && (now - lastUsed > staleThreshold || lastUsed === 0)) {
-                    var daysUnused = lastUsed > 0 ? Math.floor((now - lastUsed) / 86400000) : 999;
-                    stale.push({ name: name, daysUnused: daysUnused });
+                    // v4.6.85: never fabricate a measurement. A skill with useCount 0 and no
+                    // lastUsed has NEVER been used — reporting it as "999d unused" invented a
+                    // number that then appeared in the audit as if it had been observed.
+                    var daysUnused = lastUsed > 0 ? Math.floor((now - lastUsed) / 86400000) : null;
+                    stale.push({ name: name, daysUnused: daysUnused, neverUsed: lastUsed === 0 });
                 }
             }
             this._untrackedSkills = untracked;
diff --git a/modules/ext/skill-pack-core.js b/modules/ext/skill-pack-core.js
index 67adf80..cba77b6 100644
--- a/modules/ext/skill-pack-core.js
+++ b/modules/ext/skill-pack-core.js
@@ -1206,7 +1206,9 @@ after the behaviour itself was fixed in v4.6.58.`),
         }
         for (var s of staleSkills) {
             if (!index[s.name] || index[s.name].immune) continue;
-            stale.push(s.name + ' (' + s.daysUnused + 'd unused)');
+            stale.push(s.name + (s.daysUnused === null || s.daysUnused === undefined
+                ? ' (never used)'
+                : ' (' + s.daysUnused + 'd unused)'));
         }
 
         // 2. Duplicate check (simple Levenshtein on name)