feat(gamebook): text narration + --only + bump

--narrate-text makes WAV narration the passage text alone (the BOX-3
shows choices as buttons, no need to speak them). --only builds a
subset incrementally; library.json always lists ALL books so it never
drops tiles. Bumps ESP32_ZACUS for BOX-3 audio.

tools/gamebook/build_gamebook.py

@@ -115,7 +115,7 @@ def narration(text: str, choices: list[dict]) -> str:
 
 
 def build_book(path: Path, force: bool, dry: bool, ip: str,
-               json_only: bool = False) -> dict | None:
+               json_only: bool = False, narrate_text: bool = False) -> dict | None:
     """Synthesise + (optionally) stage one book. Returns its library entry."""
     bid = path.stem
     book = yaml.safe_load(path.read_text())
@@ -135,7 +135,11 @@ def build_book(path: Path, force: bool, dry: bool, ip: str,
         wav = f"{bid}_{pid}.wav"
         out = OUT_DIR / wav
         if not json_only:                      # text-only (BOX-3 touch) skips audio
-            if not say_wav(narration(p["text"], choices), voice, out, force):
+            # narrate_text: read only the passage text (BOX-3 shows the choices
+            # as tappable buttons, so they don't need to be spoken).
+            spoken = (" ".join(p["text"].split()) if narrate_text
+                      else narration(p["text"], choices))
+            if not say_wav(spoken, voice, out, force):
                 print(f"  ✗ synth {bid}/{pid}"); n_fail += 1; continue
         n_ok += 1
         manifest["passages"][pid] = {
@@ -169,24 +173,34 @@ def main() -> int:
     ap.add_argument("--dry-run", action="store_true", help="synthesise only, no push")
     ap.add_argument("--json-only", action="store_true",
                     help="build/push only the JSON (no WAVs) — for the BOX-3 touch UI")
+    ap.add_argument("--narrate-text", action="store_true",
+                    help="WAV narration = passage text only (no spoken choices) — for the BOX-3")
+    ap.add_argument("--only", default="", help="comma-separated book ids to build")
     args = ap.parse_args()
 
     books = sorted(p for p in BOOKS_DIR.glob("*.yaml") if p.stem not in EXCLUDE)
     if len(books) > MAX_TILES:
         print(f"note: {len(books)} books found, library shows first {MAX_TILES}")
         books = books[:MAX_TILES]
-    print(f"library: {len(books)} books -> "
+    only = {s.strip() for s in args.only.split(",") if s.strip()}
+    build_books = [p for p in books if not only or p.stem in only]
+    print(f"library: {len(books)} books (building {len(build_books)}) -> "
           f"{'(dry-run)' if args.dry_run else f'{args.ip}:/sdcard/gamebook/'}")
 
-    entries, fail = [], 0
-    for path in books:
-        e = build_book(path, args.force, args.dry_run, args.ip, args.json_only)
+    fail = 0
+    for path in build_books:
+        e = build_book(path, args.force, args.dry_run, args.ip, args.json_only,
+                       args.narrate_text)
         if e is None:
             fail += 1
             continue
         fail += e.pop("_fail")
-        entries.append(e)
 
+    # library.json always lists ALL books (so --only doesn't drop the others'
+    # tiles): build the entries straight from the YAML titles.
+    entries = [{"id": p.stem,
+                "title": fold(yaml.safe_load(p.read_text()).get("title", p.stem))[:40],
+                "book": f"{p.stem}.json"} for p in books]
     library = {"library": entries}
     (OUT_DIR / "library.json").write_text(json.dumps(library, ensure_ascii=False, indent=1))
     if not args.dry_run: