fix(settings/agents): exclude noise from drift detection

Two false positives surfaced after the Agents tab went live:

1. status (running/idle/paused) is runtime state, not config — drops in
   and out as agents pick up issues. Removed from _DRIFT_FIELDS.

2. desiredSkills compared raw, but local/* and company/* skills carry
   per-company hashes/scopes by design (sync_agents_across_companies.py
   filters local skills with a warning). Comparing them flags every
   master+mirror pair that has any local skill on master.

Now compares only paperclipai/* skills (vendor-shipped, must match).
UI shows an inline note explaining the filter.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

web-ui/src/app/settings/_components/agents-tab.tsx

@@ -336,16 +336,21 @@ export function AgentsTab() {
     <div className="space-y-4">
       <Card className="bg-surface border-rule shadow-sm">
         <CardContent className="px-5 py-4 flex items-center justify-between gap-3 flex-wrap">
-          <div className="text-[0.85rem] text-ink-muted">
-            {data.pairs.length} סוכנים × 2 חברות (CMP master / CMPA mirror)
-            {totalDrift > 0 && (
-              <span className="text-warn ms-2">
-                · {totalDrift} פערי סנכרון
-              </span>
-            )}
-            {missingCount > 0 && (
-              <span className="text-danger ms-2">· {missingCount} זוגות לא שלמים</span>
-            )}
+          <div className="space-y-1">
+            <div className="text-[0.85rem] text-ink-muted">
+              {data.pairs.length} סוכנים × 2 חברות (CMP master / CMPA mirror)
+              {totalDrift > 0 && (
+                <span className="text-warn ms-2">
+                  · {totalDrift} פערי סנכרון
+                </span>
+              )}
+              {missingCount > 0 && (
+                <span className="text-danger ms-2">· {missingCount} זוגות לא שלמים</span>
+              )}
+            </div>
+            <div className="text-[0.7rem] text-ink-light">
+              פערי skills מחושבים על paperclipai/* בלבד. local/* ו-company/* מסוננים — שם שונה בין החברות הוא צפוי.
+            </div>
           </div>
           <Button
             variant="outline"