mars: add KittenTTS voice provider (CPU-only, offline mini model)

tts.provider: kittentts, voice Luna, mini-0.8 model (80M params) per
darman. CPU-only onnxruntime inference — no GPU on mars, validated ~1x
realtime on a weaker dev box. Upstream's misaki[en]+spacy declaration is
deliberately not honored (pulls torch→CUDA, 5.6 GB); a .pth-registered
stub satisfies the dead misaki import, failing loudly if it is ever
actually used. HF model cache pre-seeded from hash-pinned store paths so
HF_HUB_OFFLINE=1 runs with zero boot-time network. Provisioner shaped by
the Mnemosyne review: uv venv --clear, root never executes python from
the venv, ownership to the container uid before anything imports, stamp
checked against venv+model files.

hosts/mars/kittentts/kitten-misaki-stub.py

@@ -0,0 +1,34 @@
+# Runtime shim for KittenTTS on a CPU-only, disk-constrained host.
+#
+# kittentts/onnx_model.py opens with `from misaki import en, espeak` — a dead import:
+# every code path that produces audio from text goes through phonemizer-fork's
+# EspeakBackend (espeak-ng via espeakng-loader); misaki.en/espeak are never called.
+# If misaki[en] were installed for real, those two imports would be a hook for the
+# whole spacy → thinc → torch → CUDA chain (~5.6 GB verified). This stub registers
+# `misaki.en` and `misaki.espeak` as import-time-only placeholders instead.
+#
+# Written into site-packages by the derivation (see pkgs/kittentts-env.nix) under
+# `sitecustomize.py`-style auto-load — actually via a `kitten_tts_stub.py` + a `.pth`
+# pointing at it, so any Python process in this env gets the stub registered before
+# any kittentts import. If KittenTTS upstream ever starts USING misaki, this shim
+# will fail loudly at import of the missing attributes (better than silent distortion),
+# and the fix becomes "install the real misaki[en]" — a deliberate, reviewed change.
+import sys
+import types
+
+_misaki = sys.modules.get("misaki")
+if _misaki is None:
+    # Avoid registering a fake parent before the real misaki loads — the base misaki
+    # (addict/regex only) is installed normally, so usually already here.
+    import misaki  # noqa: F401  (raises if base misaki is missing — loud, not silent)
+    _misaki = sys.modules["misaki"]
+
+if getattr(_misaki, "en", None) is None:
+    _stub = types.ModuleType("misaki.en")
+    sys.modules.setdefault("misaki.en", _stub)
+    _misaki.en = _stub
+
+if getattr(_misaki, "espeak", None) is None:
+    _stub2 = types.ModuleType("misaki.espeak")
+    sys.modules.setdefault("misaki.espeak", _stub2)
+    _misaki.espeak = _stub2

hosts/mars/kittentts/requirements.txt

@@ -0,0 +1,69 @@
+# Pinned requirements for the KittenTTS side-venv on mars (validated freeze, CPU-only).
+#
+# DEPENDENCY DISCIPLINE (important — this is NOT the upstream dependency set):
+# `kittentts` declares `misaki[en]` + spacy, which transitively pull torch → the whole
+# CUDA runtime (~5.6 GB with nvidia-* wheels, verified in a clean install on this box).
+# NONE of that is reachable at runtime: onnx_model.py imports `from misaki import en, espeak`
+# at module load but generate() phonemizes exclusively through `phonemizer-fork` +
+# `espeakng-loader` (espeak-ng via EspeakBackend); misaki.en/espeak glyphs are parsed but
+# never called in the ONNX path. mars has no GPU and a modest disk budget, so:
+#
+#   - install kittentts with --no-deps and enumerate its deps manually,
+#   - install base `misaki` (NOT misaki[en]) — only addict/regex,
+#   - the misaki.en import is satisfied by a stub registered in sitecustomize
+#     (kitten-misaki-stub.py, written into site-packages by the derivation).
+#
+# Freeze captured 2026-09-19 from a verified CPU-only venv (python 3.13, i5-4460,
+# generation ~= 1x realtime with the mini model, HF_HUB_OFFLINE=1).
+#
+# kittentts itself comes from a GitHub release wheel (0.8.1), not PyPI (PyPI's 0.1.3 is
+# the old v0.1-lineage); see pkgs/kittentts-env.nix.
+addict==2.4.0
+anyio==4.15.1
+attrs==26.1.0
+babel==2.18.0
+certifi==2026.7.22
+cffi==2.1.1
+click==8.5.0
+cloudpickle==3.1.2
+csvw==4.1.0
+dlinfo==2.0.0
+docopt==0.6.2
+espeakng-loader==0.2.4
+filelock==4.0.1
+flatbuffers==25.12.19
+fsspec==2026.9.0
+h11==0.16.0
+hf-xet==1.6.0
+httpcore==1.0.9
+httpx==0.28.1
+huggingface-hub==1.32.0
+idna==3.20
+isodate==0.7.2
+joblib==1.6.0
+jsonschema-specifications==2025.9.1
+jsonschema==4.26.0
+language-tags==1.3.1
+misaki==0.9.4
+num2words==0.5.14
+numpy==2.5.3
+onnxruntime==1.30.0
+packaging==26.3
+phonemizer-fork==3.3.2
+protobuf==7.36.2
+pycparser==3.0
+pyparsing==3.3.2
+python-dateutil==2.9.0.post0
+pyyaml==6.0.3
+rdflib==7.6.0
+referencing==0.37.0
+regex==2026.9.10
+rfc3986==1.5.0
+rpds-py==2026.6.3
+segments==2.4.0
+six==1.17.0
+soundfile==0.14.0
+termcolor==3.3.0
+tqdm==4.70.1
+typing-extensions==4.16.0
+uritemplate==4.2.0