PAP-57: IA Phase 2 — rename user-facing "Issues" → "Tasks" copy

Copy-only sweep across ui/src: nav (sidebar + mobile), Tasks list page
(headings, breadcrumbs, buttons, empty states, filters, column headers,
toasts, aria-labels), task detail, dialogs, command palette, inbox,
search, dashboards, project/agent/workspace pages, recovery/blocked
notices, and design-guide demos.

Routes stay at /issues; internal symbols (Issue, issueId, queryKeys,
kind: "issue"), API fields, and backend-matched protocol strings
(successful-run-handoff notice bodies) are unchanged. Tests updated to
match the new copy. Developer-only *UxLab/*Perf harness pages left as-is.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Co-Authored-By: Paperclip <noreply@paperclip.ing>

ui/src/components/NewIssueDialog.tsx

@@ -316,7 +316,7 @@ const IssueTitleTextarea = memo(function IssueTitleTextarea({
   return (
     <textarea
       className="w-full text-lg font-semibold bg-transparent outline-none resize-none overflow-hidden placeholder:text-muted-foreground/50"
-      placeholder="Issue title"
+      placeholder="Task title"
       rows={1}
       value={draftValue}
       onChange={(e) => {
@@ -1145,7 +1145,7 @@ export function NewIssueDialog() {
   const hasSavedDraft = Boolean(savedDraft?.title.trim() || savedDraft?.description.trim());
   const canDiscardDraft = hasDraft || hasSavedDraft;
   const createIssueErrorMessage =
-    createIssue.error instanceof Error ? createIssue.error.message : "Failed to create issue. Try again.";
+    createIssue.error instanceof Error ? createIssue.error.message : "Failed to create task. Try again.";
   const stagedDocuments = stagedFiles.filter((file) => file.kind === "document");
   const stagedAttachments = stagedFiles.filter((file) => file.kind === "attachment");
 
@@ -1294,7 +1294,7 @@ export function NewIssueDialog() {
               </PopoverContent>
             </Popover>
             <span className="text-muted-foreground/60">&rsaquo;</span>
-            <span>{isSubIssueMode ? "New sub-issue" : "New issue"}</span>
+            <span>{isSubIssueMode ? "New sub-task" : "New task"}</span>
           </div>
           <div className="flex items-center gap-1">
             <Button
@@ -1579,7 +1579,7 @@ export function NewIssueDialog() {
             <div className="max-w-full rounded-md border border-border bg-muted/30 px-2.5 py-1.5 text-xs text-muted-foreground">
               <div className="flex items-center gap-1.5">
                 <ListTree className="h-3.5 w-3.5 shrink-0" />
-                <span className="shrink-0">Sub-issue of</span>
+                <span className="shrink-0">Sub-task of</span>
                 <span className="font-medium text-foreground">{parentIssueLabel}</span>
               </div>
               {newIssueDefaults.parentTitle ? (
@@ -1596,7 +1596,7 @@ export function NewIssueDialog() {
             <div className="space-y-1.5">
               <div className="text-xs font-medium">Execution workspace</div>
               <div className="text-[11px] text-muted-foreground">
-                Control whether this issue runs in the shared workspace, a new isolated workspace, or an existing one.
+                Control whether this task runs in the shared workspace, a new isolated workspace, or an existing one.
               </div>
               <select
                 className="w-full rounded border border-border bg-transparent px-2 py-1.5 text-xs outline-none"
@@ -1635,7 +1635,7 @@ export function NewIssueDialog() {
               )}
               {showParentWorkspaceWarning ? (
                 <div className="rounded-md border border-amber-300/60 bg-amber-50 px-2 py-1.5 text-[11px] text-amber-900 dark:border-amber-800/70 dark:bg-amber-950/30 dark:text-amber-100">
-                  Warning: this sub-issue will no longer use the parent issue workspace{parentExecutionWorkspaceLabel ? ` (${parentExecutionWorkspaceLabel})` : ""}.
+                  Warning: this sub-task will no longer use the parent task workspace{parentExecutionWorkspaceLabel ? ` (${parentExecutionWorkspaceLabel})` : ""}.
                 </div>
               ) : null}
             </div>
@@ -1694,7 +1694,7 @@ export function NewIssueDialog() {
                     <p className="text-[11px] text-muted-foreground">Runs on the agent's primary model.</p>
                   )}
                   {assigneeModelLane === "custom" && (
-                    <p className="text-[11px] text-muted-foreground">Override the model and effort for this issue only.</p>
+                    <p className="text-[11px] text-muted-foreground">Override the model and effort for this task only.</p>
                   )}
                 </div>
                 {assigneeModelLane === "custom" && (
@@ -2079,7 +2079,7 @@ export function NewIssueDialog() {
             >
               <span className="inline-flex items-center justify-center gap-1.5">
                 {createIssue.isPending ? <Loader2 className="h-3.5 w-3.5 animate-spin" /> : null}
-                <span>{createIssue.isPending ? "Creating..." : isSubIssueMode ? "Create Sub-Issue" : "Create Issue"}</span>
+                <span>{createIssue.isPending ? "Creating..." : isSubIssueMode ? "Create Sub-Task" : "Create Task"}</span>
               </span>
             </Button>
           </div>