refactor(nexus): vocabulary sweep company -> workspace (phase 16b)

Replace user-visible "company" display strings with "workspace"
in the workspace rail, agent detail, and workspace settings page.
Code identifiers, API paths, and types remain on the upstream
"company" vocabulary per PROJECT.md sync constraint.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/components/CompanyRail.tsx

@@ -314,13 +314,13 @@ export function CompanyRail() {
             <button
               onClick={() => openOnboarding()}
               className="flex items-center justify-center w-11 h-11 rounded-[22px] hover:rounded-[14px] border-2 border-dashed border-border text-muted-foreground hover:border-foreground/30 hover:text-foreground transition-[border-color,color,border-radius] duration-150"
-              aria-label="Add company"
+              aria-label="Add workspace"
             >
               <Plus className="h-5 w-5" />
             </button>
           </TooltipTrigger>
           <TooltipContent side="right" sideOffset={8}>
-            <p>Add company</p>
+            <p>Add workspace</p>
           </TooltipContent>
         </Tooltip>
       </div>

ui/src/pages/AgentDetail.tsx

@@ -1534,7 +1534,7 @@ function ConfigurationTab({
       : taskAssignSource === "agent_creator"
         ? "Enabled automatically while this agent can create new agents."
         : taskAssignSource === "explicit_grant"
-          ? "Enabled via explicit company permission grant."
+          ? "Enabled via explicit workspace permission grant."
           : "Disabled unless explicitly granted.";
 
   return (
@@ -2746,7 +2746,7 @@ function AgentSkillsTab({
 
           {desiredOnlyMissingSkills.length > 0 && (
             <div className="rounded-xl border border-warning/60 bg-warning/60 px-4 py-3 text-sm text-warning">
-              <div className="font-medium">Requested skills missing from the company library</div>
+              <div className="font-medium">Requested skills missing from the workspace library</div>
               <div className="mt-1 text-xs">
                 {desiredOnlyMissingSkills.join(", ")}
               </div>

ui/src/pages/CompanySettings.tsx

@@ -268,13 +268,13 @@ export function CompanySettings() {
           </Field>
           <Field
             label="Description"
-            hint="Optional description shown in the company profile."
+            hint="Optional description shown in the workspace profile."
           >
             <input
               className="w-full rounded-md border border-border bg-transparent px-2.5 py-1.5 text-sm outline-none"
               type="text"
               value={description}
-              placeholder="Optional company description"
+              placeholder="Optional workspace description"
               onChange={(e) => setDescription(e.target.value)}
             />
           </Field>
@@ -340,7 +340,7 @@ export function CompanySettings() {
               </Field>
               <Field
                 label="Brand color"
-                hint="Sets the hue for the company icon. Leave empty for auto-generated color."
+                hint="Sets the hue for the workspace icon. Leave empty for auto-generated color."
               >
                 <div className="flex items-center gap-2">
                   <input
@@ -604,13 +604,13 @@ export function CompanySettings() {
                 ? "Archiving..."
                 : selectedCompany.status === "archived"
                 ? "Already archived"
-                : "Archive company"}
+                : "Archive workspace"}
             </Button>
             {archiveMutation.isError && (
               <span className="text-xs text-destructive">
                 {archiveMutation.error instanceof Error
                   ? archiveMutation.error.message
-                  : "Failed to archive company"}
+                  : "Failed to archive workspace"}
               </span>
             )}
           </div>