feat: chapter labels, staff draft visibility, and chat FAB mobile fix

- Rename chapter labels from "هفتهٔ N" to "فصل N" in skill-tree
  - Show dashed "پیش‌نویس" badge on unpublished chapters/lessons for staff
  - Add isPublished to TreeLesson type (backend already exposes it)
  - Fix chat FAB and notification banner overlapping bottom nav on mobile

frontend/src/components/mentor-chat.tsx

@@ -3269,7 +3269,7 @@ ws.onmessage = (ev) => {
               setOpen(true);
               setNotif(null);
             }}
-            className="fixed bottom-24 start-5 end-5 z-[64] flex max-w-full items-center gap-2.5 rounded-2xl border-2 border-white/50 bg-card/85 p-2.5 text-right shadow-offset backdrop-blur-2xl sm:end-auto sm:max-w-[300px]"
+            className="fixed bottom-[calc(5.5rem+env(safe-area-inset-bottom,0px))] start-5 end-5 z-[64] flex max-w-full items-center gap-2.5 rounded-2xl border-2 border-white/50 bg-card/85 p-2.5 text-right shadow-offset backdrop-blur-2xl sm:bottom-24 sm:end-auto sm:max-w-[300px]"
           >
             <span className="grid h-9 w-9 shrink-0 place-items-center rounded-xl bg-accent/15">
               <MessageSquare className="h-4 w-4 text-accent" />
@@ -3286,7 +3286,9 @@ ws.onmessage = (ev) => {
       </AnimatePresence>
 
       {me && !open && (
-        <div className="fixed bottom-5 start-5 z-[64]">
+        // On mobile the bottom nav is 56px; lift FAB above it + safe area + gap.
+        // md:bottom-5 restores original position when the bottom nav is hidden.
+        <div className="fixed bottom-[calc(4.5rem+env(safe-area-inset-bottom,0px))] start-5 z-[64] md:bottom-5">
           <div className="relative">
             {unreadTotal > 0 && (
               <span className="pointer-events-none absolute -inset-1 -z-10 animate-ping rounded-2xl bg-accent/40" aria-hidden />

frontend/src/components/skill-tree.tsx

@@ -21,6 +21,7 @@ import {
 } from "lucide-react";
 import { useMemo, useState } from "react";
 import type { TreeChapter, TreeData, TreeLesson } from "@/lib/types";
+import { useAuth } from "@/lib/auth-store";
 import { cn, formatFaNumber } from "@/lib/utils";
 
 const CHAPTER_ICONS: Record<string, typeof Terminal> = {
@@ -38,6 +39,8 @@ const CHAPTER_ICONS: Record<string, typeof Terminal> = {
 
 export function SkillTree({ data, onSelect }: { data: TreeData; onSelect?: (id: number) => void }) {
   const router = useRouter();
+  const role = useAuth((s) => s.user?.role);
+  const isStaff = role === "admin" || role === "mentor";
 
   const chapters = useMemo(() => [...data.chapters].sort((a, b) => a.sortOrder - b.sortOrder), [data]);
   const byId = useMemo(() => {
@@ -97,6 +100,7 @@ export function SkillTree({ data, onSelect }: { data: TreeData; onSelect?: (id:
             open={expanded.has(ch.id)}
             onToggle={() => toggle(ch.id)}
             onSelect={onSelect ?? ((id: number) => router.push(`/player/${id}`))}
+            isStaff={isStaff}
           />
         ))}
       </div>
@@ -110,12 +114,14 @@ function ChapterRow({
   open,
   onToggle,
   onSelect,
+  isStaff,
 }: {
   ch: TreeChapter;
   byId: Map<number, TreeLesson>;
   open: boolean;
   onToggle: () => void;
   onSelect: (id: number) => void;
+  isStaff: boolean;
 }) {
   const lessons = [...(ch.lessons ?? [])].sort((a, b) => a.y - b.y || a.x - b.x);
   const done = lessons.filter((l) => l.progress?.passedQuiz).length;
@@ -147,8 +153,13 @@ function ChapterRow({
                 <CheckCircle2 className="h-3.5 w-3.5" /> کامل شد
               </span>
             )}
+            {isStaff && !ch.isPublished && (
+              <span className="hidden shrink-0 rounded-full border border-dashed border-warning/50 bg-warning/10 px-2 py-0.5 text-[11px] font-bold text-warning sm:inline-block">
+                پیش‌نویس
+              </span>
+            )}
             <span className="hidden shrink-0 rounded-full bg-muted px-2 py-0.5 text-[11px] font-bold text-muted-foreground sm:inline-block">
-              هفتهٔ {ch.sortOrder}
+              فصل {ch.sortOrder}
             </span>
           </div>
           <p className="truncate text-xs text-muted-foreground">{ch.description}</p>
@@ -173,7 +184,7 @@ function ChapterRow({
         <div className="overflow-hidden">
           <div className="grid gap-2.5 border-t-2 border-border/70 p-4 sm:grid-cols-2">
             {lessons.map((lesson) => (
-              <LessonRow key={lesson.id} lesson={lesson} byId={byId} onSelect={onSelect} />
+              <LessonRow key={lesson.id} lesson={lesson} byId={byId} onSelect={onSelect} isStaff={isStaff} />
             ))}
           </div>
         </div>
@@ -186,10 +197,12 @@ function LessonRow({
   lesson,
   byId,
   onSelect,
+  isStaff,
 }: {
   lesson: TreeLesson;
   byId: Map<number, TreeLesson>;
   onSelect: (id: number) => void;
+  isStaff: boolean;
 }) {
   const passed = !!lesson.progress?.passedQuiz;
   const locked = lesson.locked;
@@ -254,6 +267,11 @@ function LessonRow({
         </div>
         <div className="mt-1.5 flex flex-wrap items-center gap-2">
           <span className={cn("rounded-full px-2 py-0.5 text-[11px] font-bold", s.pill)}>{s.pillText}</span>
+          {isStaff && lesson.isPublished === false && (
+            <span className="rounded-full border border-dashed border-warning/50 bg-warning/10 px-2 py-0.5 text-[11px] font-bold text-warning">
+              پیش‌نویس
+            </span>
+          )}
           {inProgress && (
             <div className="h-1.5 w-24 overflow-hidden rounded-full bg-muted">
               <div className="h-full rounded-full bg-primary" style={{ width: `${pct}%` }} />

frontend/src/lib/types.ts

@@ -117,6 +117,7 @@ export interface TreeLesson {
   xpReward: number;
   durationSeconds: number;
   chapterId: number;
+  isPublished?: boolean;
 }
 
 export interface TreeChapter extends Chapter {