Add static Piper asset service

PIPER_VOICE_NOTICES.txt

@@ -0,0 +1,26 @@
+Swedish Piper voice models
+==========================
+
+This service distributes the Swedish medium Piper models Alma, Lisa, and NST
+from the rhasspy/piper-voices repository, pinned to revision
+c10ece1aade47bb51c153c893d14e5bf8e5b7117. Model weights are published under
+/static/piper-wasm-v1/voices/ after integrity verification in CI.
+
+Alma (sv_SE-alma-medium)
+Source: https://huggingface.co/rhasspy/piper-voices/tree/c10ece1aade47bb51c153c893d14e5bf8e5b7117/sv/sv_SE/alma/medium
+The model card states CC BY 4.0 and identifies the upstream voice project at
+https://huggingface.co/yeagersthlm/piper-voice-sv-alma.
+
+Lisa (sv_SE-lisa-medium)
+Source: https://huggingface.co/rhasspy/piper-voices/tree/c10ece1aade47bb51c153c893d14e5bf8e5b7117/sv/sv_SE/lisa/medium
+The upstream model card describes this as fine-tuned from the Norwegian
+talesyntese medium voice.
+
+NST (sv_SE-nst-medium)
+Source: https://huggingface.co/rhasspy/piper-voices/tree/c10ece1aade47bb51c153c893d14e5bf8e5b7117/sv/sv_SE/nst/medium
+The upstream model card identifies the NST Swedish TTS dataset as CC0 and
+credits KBLab at the National Library of Sweden for training the voice.
+
+The upstream model files and model cards remain the source of truth for license
+terms. Exact source revision and per-file integrity checks are in
+scripts/assets.mjs.