[9ef46be7] feat(prompter): implement Prompter page, nav entry, chat UI, and task creation wiring (#78) (#79)

- Add Task Assistant nav entry (Sparkles icon) to sidebar between Kanban and Projects
- Create lib/api/prompter.ts with createSession, sendMessage, getDraft API functions
- Create hooks/use-prompter.ts with 6-state machine (empty→chatting→draft_preview→review_modal→launching→success)
- Create ChatMessages with auto-scroll, user/assistant/error rendering, inline DraftProposalCard
- Create ChatComposer with Enter-to-send and Shift+Enter for newline
- Create DraftProposalCard with title, description, acceptance criteria, metadata badges, Keep Chatting/Review & Confirm actions
- Create ConfirmDialog (Radix Dialog, no form element) with MarkdownEditor, AcceptanceCriteriaEditor, metadata selects, warning banner, disabled Confirm & Launch until valid
- Create SuccessCard with task title, team, View Task link, Start Another button
- Create /prompter route page composing all components via usePrompter hook
- TypeScript and ESLint pass with zero errors

Co-authored-by: Frontend Developer 2 <fe-dev-2@agents.roboco.dev>

panel/src/app/(dashboard)/prompter/page.tsx

@@ -0,0 +1,93 @@
+"use client";
+
+import { Sparkles } from "lucide-react";
+import { usePrompter } from "@/hooks/use-prompter";
+import {
+  ChatMessages,
+  ChatComposer,
+  ConfirmDialog,
+  SuccessCard,
+} from "@/components/prompter";
+
+export default function PrompterPage() {
+  const {
+    state,
+    messages,
+    isSending,
+    editableDraft,
+    createdTaskId,
+    createdTaskTitle,
+    createdTaskTeam,
+    send,
+    openReview,
+    closeReview,
+    keepChatting,
+    updateDraft,
+    isValidForLaunch,
+    launchTask,
+    startAnother,
+    isLaunching,
+  } = usePrompter();
+
+  const isComposerDisabled =
+    state === "launching" || state === "success";
+
+  return (
+    <div className="flex h-full flex-col">
+      {/* Page header */}
+      <div className="flex items-center gap-3 border-b px-6 py-4">
+        <Sparkles className="h-5 w-5 text-primary" />
+        <div>
+          <h1 className="text-lg font-semibold">Task Assistant</h1>
+          <p className="text-xs text-muted-foreground">
+            Describe your idea and I&apos;ll help you create a structured task
+          </p>
+        </div>
+      </div>
+
+      {/* Chat area */}
+      <div className="flex flex-1 flex-col overflow-hidden">
+        {/* Success overlay in chat area */}
+        {state === "success" &&
+          createdTaskId &&
+          createdTaskTitle &&
+          createdTaskTeam ? (
+          <div className="flex flex-1 flex-col items-center justify-center px-8 py-8">
+            <div className="w-full max-w-md">
+              <SuccessCard
+                taskId={createdTaskId}
+                taskTitle={createdTaskTitle}
+                team={createdTaskTeam}
+                onStartAnother={startAnother}
+              />
+            </div>
+          </div>
+        ) : (
+          <ChatMessages
+            messages={messages}
+            onOpenReview={openReview}
+            onKeepChatting={keepChatting}
+          />
+        )}
+
+        {/* Composer */}
+        <ChatComposer
+          onSend={send}
+          disabled={isComposerDisabled}
+          isSending={isSending}
+        />
+      </div>
+
+      {/* Confirmation dialog (portal) */}
+      <ConfirmDialog
+        open={state === "review_modal" || state === "launching"}
+        draft={editableDraft}
+        onClose={closeReview}
+        onUpdate={updateDraft}
+        onConfirm={launchTask}
+        isLaunching={isLaunching}
+        isValid={isValidForLaunch()}
+      />
+    </div>
+  );
+}