Switch to Docker SDK with CMAKE_BUILD_PARALLEL_LEVEL=1 to fix OOMKilled build

Fix OOMKilled build: switch to CPU-only torch (225MB vs 2.4GB CUDA wheel)

Switch TTS: kokoro+misaki+spacy+blis → piper-tts (onnxruntime, Python 3.13 safe)

Fix: kokoro+misaki pinned to 0.7.4 (Python 3.13 compatible)

Fix: kokoro 0.9.4 → 0.7.16 (Python 3.13 compatible)

Fix README colorFrom: violet → purple (HF validation)

Initial deployment — Lulluna bedtime story weaver