Simplify connection cost field label

Just "Cost", not "Cost override" -- there's no per-type default cost
set, and there isn't meant to be one right now (pricing varies too
much across cable grades), so "override" implied a relationship that
doesn't exist yet.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017DUU6CnxECCDeqDNYJgr5x

src/components/inspector/ConnectionInspector.tsx

@@ -79,7 +79,7 @@ export default function ConnectionInspector({ connectionId }: { connectionId: st
       </label>
 
       <label className="block text-xs font-medium text-slate-600">
-        Cost override
+        Cost
         <div className="mt-1 flex items-center gap-2">
           <span className="text-xs text-slate-500">$</span>
           <input
@@ -95,14 +95,11 @@ export default function ConnectionInspector({ connectionId }: { connectionId: st
             className="w-full rounded border border-slate-300 px-2 py-1 text-sm"
             placeholder={
               cableCostPerUnit !== undefined && connection.distance
-                ? `computed: $${(cableCostPerUnit * connection.distance).toFixed(2)}`
+                ? `e.g. ${(cableCostPerUnit * connection.distance).toFixed(2)}`
                 : 'e.g. 24.99'
             }
           />
         </div>
-        <p className="mt-1 text-[10px] text-slate-400">
-          Overrides the cable type's per-unit cost for this run specifically. Leave blank to use cost/unit × distance.
-        </p>
       </label>
 
       <label className="block text-xs font-medium text-slate-600">