feat(pi-family): guestSetup seam + board-branded workspace texts

Overlay QEMU-Linux boards are not Raspberry Pis: ProBoardDef.guestSetup
lets a board send one shell line at the boot prompt (hostname/PS1/clear)
to de-brand the generic image, sent before piBooted flips so uploads
cannot interleave; the workspace start button and power-on title carry
the board's own label for non raspberry-pi kinds; the compile console
line uses the board label instead of 'Raspberry Pi 3B'.

frontend/src/components/editor/EditorToolbar.tsx

@@ -502,9 +502,9 @@ export const EditorToolbar = ({
     const blog = (type: CompilationLog['type'], message: string) =>
       addLog({ timestamp: new Date(), type, message, target: boardTarget });
 
-    // Raspberry Pi 3B doesn't need arduino-cli compilation
+    // QEMU-Linux boards don't need arduino-cli compilation
     if (isPiBoardKind(kind)) {
-      blog('info', 'Raspberry Pi 3B: no compilation needed — run Python scripts directly.');
+      blog('info', `${boardLabel}: no compilation needed — run Python scripts directly.`);
       setMessage({ type: 'success', text: 'Ready (no compilation needed)' });
       setCompiling(false);
       return;

frontend/src/components/raspberry-pi/RaspberryPiWorkspace.tsx

@@ -75,6 +75,15 @@ export const RaspberryPiWorkspace: React.FC<RaspberryPiWorkspaceProps> = ({ boar
   // Display the active board's real name (Pi 3B / 4B / 5 / Zero / …) instead of
   // a hardcoded "Raspberry Pi 3B" — the workspace serves the whole Pi family.
   const boardLabel = board ? boardDisplayName(board) : 'Raspberry Pi';
+  // Overlay QEMU-Linux boards (piFamily kinds) are not Raspberry Pis — their
+  // start button / power title must carry the board's own name.
+  const isRaspberry = !board || board.boardKind.startsWith('raspberry-pi');
+  const startLabel = isRaspberry
+    ? t('editor.pi.startPi')
+    : t('editor.pi.startBoard', { board: boardLabel, defaultValue: 'Start {{board}}' });
+  const powerOnTitle = isRaspberry
+    ? t('editor.pi.powerOnTitle')
+    : t('editor.pi.powerOnBoardTitle', { board: boardLabel, defaultValue: 'Power on {{board}}' });
 
   // Three display states: offline (!running) → booting (running, guest Linux
   // still coming up) → ready (running + booted shell). `running` flips on click
@@ -193,9 +202,9 @@ export const RaspberryPiWorkspace: React.FC<RaspberryPiWorkspaceProps> = ({ boar
               <button
                 style={{ ...styles.toolbarBtn, color: '#4caf50', borderColor: '#4caf50' }}
                 onClick={() => startBoard(boardId)}
-                title={t('editor.pi.powerOnTitle')}
+                title={powerOnTitle}
               >
-                <PlayIcon />{t('editor.pi.startPi')}
+                <PlayIcon />{startLabel}
               </button>
             ) : (
               <>
@@ -268,7 +277,7 @@ export const RaspberryPiWorkspace: React.FC<RaspberryPiWorkspaceProps> = ({ boar
                 <div style={styles.offlineTitle}>{t('editor.pi.offlineTitle', { board: boardLabel })}</div>
                 <div style={styles.offlineSubtitle}>{t('editor.pi.offlineSubtitle')}</div>
                 <button style={styles.startBtn} onClick={() => startBoard(boardId)}>
-                  <PlayIcon />{t('editor.pi.startPi')}
+                  <PlayIcon />{startLabel}
                 </button>
                 <div style={styles.offlineNote}>
                   {t('editor.pi.offlineNote1')}

frontend/src/lib/proBoardRegistry.ts

@@ -59,6 +59,10 @@ export interface ProBoardDef {
    *  bridge (backend qemu WebSocket, VFS panel, boot terminal). The overlay
    *  must also register a matching backend profile for the kind. */
   piFamily?: boolean;
+  /** One shell line sent to the guest right after it reaches the boot
+   *  prompt (piFamily boards only). Lets a board de-brand the generic
+   *  image, e.g. set its own hostname/PS1 and clear the stock motd. */
+  guestSetup?: string;
   /** Canvas renderer. Receives the placed board's props; return a React node.
    *  When omitted, the canvas renders `<tag id=... style=absolute@x,y>`. */
   render?: (props: { id: string; x: number; y: number; running: boolean }) => React.ReactNode;

frontend/src/store/useSimulatorStore.ts

@@ -1244,11 +1244,23 @@ export const useSimulatorStore = create<SimulatorState>((set, get) => {
         };
         // Guest Linux finished booting (shell prompt reached). Flip piBooted so
         // the workspace swaps the "Booting…" overlay for the live terminal and
-        // uploads know the shell is ready.
+        // uploads know the shell is ready. Overlay boards may declare a
+        // guestSetup line (hostname/PS1/clear) to de-brand the generic image;
+        // it runs before piBooted flips so the VFS upload (gated on piBooted)
+        // cannot interleave with it.
         bridge.onBooted = () => {
-          set((s) => ({
-            boards: s.boards.map((b) => (b.id === id ? { ...b, piBooted: true } : b)),
-          }));
+          const setup = getProBoard(boardKind)?.guestSetup;
+          const flip = () =>
+            set((s) => ({
+              boards: s.boards.map((b) => (b.id === id ? { ...b, piBooted: true } : b)),
+            }));
+          if (setup) {
+            void bridge
+              .sendAndWaitForPrompt(setup.endsWith('\n') ? setup : setup + '\n')
+              .then(flip);
+          } else {
+            flip();
+          }
         };
         bridge.onDisconnected = () => {
           set((s) => {