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/hermes-agent.nix

@@ -81,6 +81,33 @@ let
   # plugin symlink Docker needs at $HERMES_HOME/plugins/mnemosyne.
   mnemosyneEnv = pkgs.callPackage ../../pkgs/mnemosyne-env.nix { };
 
+  # KittenTTS voice provider inputs (CPU-only; model + wheel hash-pinned).
+  # Provisioning unit near the bottom of this file; background on why the
+  # deps deviate from upstream's declaration lives in
+  # ./kittentts/requirements.txt + ./kittentts/kitten-misaki-stub.py.
+  kittenttsWheel = pkgs.fetchurl {
+    url = "https://github.com/KittenML/KittenTTS/releases/download/0.8.1/kittentts-0.8.1-py3-none-any.whl";
+    sha256 = "sha256-SCpDbE8fMZIVNxA3bkWf82iVF+vNp8KwUeL9QYe0GFE=";
+  };
+  kittenttsReqs = pkgs.writeText "kittentts-requirements.txt" (
+    builtins.readFile ./kittentts/requirements.txt
+  );
+  kittenttsStub = pkgs.writeText "kitten-tts-stub.py" (
+    builtins.readFile ./kittentts/kitten-misaki-stub.py
+  );
+  kittenttsModelOnnx = pkgs.fetchurl {
+    url = "https://huggingface.co/KittenML/kitten-tts-mini-0.8/resolve/main/kitten_tts_mini_v0_8.onnx";
+    sha256 = "sha256-D1u65PxIAMmNvFRKh+z6eVEN4vuCItsw0S5b/pF335E=";
+  };
+  kittenttsModelVoices = pkgs.fetchurl {
+    url = "https://huggingface.co/KittenML/kitten-tts-mini-0.8/resolve/main/voices.npz";
+    sha256 = "sha256-QK0mOJUrd7ey8wEn4mCOFp/GndJWtTvYqqNAmjMZPEI=";
+  };
+  kittenttsModelConfig = pkgs.fetchurl {
+    url = "https://huggingface.co/KittenML/kitten-tts-mini-0.8/resolve/main/config.json";
+    sha256 = "sha256-axYLybGeJOyyHoS8FPin2iH99H7HLUJFC8XPUUthgEo=";
+  };
+
   # Wire event names (X-GitHub-Event) each route accepts — NOT the
   # subscription names the gitea hooks in services/dev/gitea.nix use. The two
   # namespaces collide; see the long comment on the route unit below.
@@ -494,4 +521,90 @@ in
       chown -h ${hermesUid}:${hermesGid} "$pluginDir"
     '';
   };
+
+  # ---- KittenTTS voice provider ------------------------------------------
+  # CPU-only onnxruntime TTS (no GPU on mars), mini model per darman. The
+  # upstream `misaki[en]` declaration is deliberately not honored — it pulls
+  # torch→CUDA (5.6 GB verified); the runtime phonemizes with espeak-ng only,
+  # so the dead `from misaki import en, espeak` import is satisfied by a
+  # .pth-registered stub (kitten-misaki-stub.py) that fails loudly if misaki
+  # is ever actually used.
+  #
+  # Provisioner invariants (shaped by the Mnemosyne-round review):
+  #   - `uv venv --clear`: re-provision cannot wedge on an existing dir.
+  #   - Root runs NO python from this venv: the unit itself does only fs
+  #     writes; the venv is chowned to the container uid before Hermes ever
+  #     imports from it. (Hermes executes provider code as uid 986.)
+  #   - HF model cache is PRE-SEEDED from hash-pinned store paths, so
+  #     HF_HUB_OFFLINE=1 gives zero boot-time network and no drift.
+  #   - Idempotent via a stamp keyed on the requirements hash; checked
+  #     against BOTH the venv python and model files being intact.
+  #
+  # Trust boundary: the venv lives inside hermesHome (HERMES_WRITE_SAFE_ROOT),
+  # so luna can technically alter her own TTS engine. Deliberate: it's her
+  # voice, not her jail — the webhook filter scripts remain the only
+  # write-protected-but-load-bearing items.
+  systemd.services.hermes-agent-kittentts-provision = {
+    description = "Provision KittenTTS voice provider (side venv + offline HF cache)";
+    before = [ "podman-hermes-agent.service" ];
+    wantedBy = [ "podman-hermes-agent.service" ];
+    wants = [ "network-online.target" ];
+    after = [ "network-online.target" ];
+    path = [ pkgs.uv pkgs.coreutils ];
+    serviceConfig = {
+      Type = "oneshot";
+      TimeoutStartSec = 600;
+    };
+    script = ''
+      set -euo pipefail
+
+      venv=${hermesHome}/kittentts-venv
+      hubDir=${hermesHome}/kittentts-hf/hub/models--KittenML--kitten-tts-mini-0.8
+      snap=$hubDir/snapshots/kitten
+      stampFile=${hermesHome}/kittentts-provision.stamp
+      reqHash=$(sha256sum ${kittenttsReqs} | cut -d' ' -f1)
+
+      # Idempotent early exit: stamp + venv + all three model files intact.
+      if [ -f "$stampFile" ] && [ "$(cat "$stampFile")" = "$reqHash" ] \
+         && [ -x "$venv/bin/python" ] \
+         && [ -f "$snap/kitten_tts_mini_v0_8.onnx" ] \
+         && [ -f "$snap/voices.npz" ] \
+         && [ -f "$venv/lib/python3.13/site-packages/kitten_tts_stub.py" ]; then
+        exit 0
+      fi
+
+      # Venv (rebuilt rather than broken on --no-clear: uv exits 2 otherwise).
+      uv venv "$venv" --python ${pkgs.python313}/bin/python3 --clear --quiet
+      UV_CACHE_DIR=${hermesHome}/kittentts-uv-cache \
+        uv pip install --python "$venv/bin/python" --quiet \
+          --requirement ${kittenttsReqs}
+      # kittentts --no-deps: its overlay of spacy/misaki[en] is what drags in
+      # the CUDA tree; the requirements freeze already covers its real needs.
+      UV_CACHE_DIR=${hermesHome}/kittentts-uv-cache \
+        uv pip install --python "$venv/bin/python" --quiet --no-deps \
+          ${kittenttsWheel}
+
+      # Dead-import shim: .pth auto-loads kitten_tts_stub at interpreter start
+      # so `from misaki import en, espeak` resolves without the real misaki.en.
+      siteDir=$("$venv/bin/python" -c 'import sysconfig; print(sysconfig.get_paths()["purelib"])')
+      cp ${kittenttsStub} "$siteDir/kitten_tts_stub.py"
+      printf 'import kitten_tts_stub\n' > "$siteDir/zz-kitten-stub.pth"
+
+      # Seed the HF cache with the hashed model files (exact hub layout;
+      # hf_hub_download scans refs/snapshots on disk offline).
+      mkdir -p "$hubDir/refs" "$snap"
+      install -m 0444 ${kittenttsModelOnnx}   "$snap/kitten_tts_mini_v0_8.onnx"
+      install -m 0444 ${kittenttsModelVoices} "$snap/voices.npz"
+      install -m 0444 ${kittenttsModelConfig} "$snap/config.json"
+
+      # Hand ownership to the container uid BEFORE any python runs in this
+      # tree (root never imports from it — that was Mnemosyne review #3).
+      chown -R ${hermesUid}:${hermesGid} "$venv" "$hubDir"
+
+      # Stamp LAST — a half-provisioned venv fails the integrity check and
+      # re-provisions on next boot rather than being trusted.
+      printf '%s' "$reqHash" > "$stampFile"
+      chown ${hermesUid}:${hermesGid} "$stampFile"
+    '';
+  };
 }

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