feat: character system v2 — schema upgrade, memory system, per-character TTS routing

Character schema v2: background, dialogue_style, appearance, skills, gaze_presets
with automatic v1→v2 migration. LLM-assisted character creation via Character MCP
server. Two-tier memory system (personal per-character + general shared) with
budget-based injection into LLM system prompt. Per-character TTS voice routing via
state file — Wyoming TTS server reads active config to route between Kokoro (local)
and ElevenLabs (cloud PCM 24kHz). Dashboard: memories page, conversation history,
character profile on cards, auto-TTS engine selection from character config.
Also includes VTube Studio expression bridge and ComfyUI API guide.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.env.example

@@ -9,6 +9,7 @@ OPENAI_API_KEY=
 DEEPSEEK_API_KEY=
 GEMINI_API_KEY=
 ELEVENLABS_API_KEY=
+GAZE_API_KEY=
 
 # ─── Data & Paths ──────────────────────────────────────────────────────────────
 DATA_DIR=${HOME}/homeai-data
@@ -40,10 +41,14 @@ OPEN_WEBUI_URL=http://localhost:3030
 OLLAMA_PRIMARY_MODEL=llama3.3:70b
 OLLAMA_FAST_MODEL=qwen2.5:7b
 
+# Medium model kept warm for voice pipeline (override per persona)
+# Used by preload-models.sh keep-warm daemon
+HOMEAI_MEDIUM_MODEL=qwen3.5:35b-a3b
+
 # ─── P3: Voice ─────────────────────────────────────────────────────────────────
 WYOMING_STT_URL=tcp://localhost:10300
 WYOMING_TTS_URL=tcp://localhost:10301
-ELEVENLABS_API_KEY=              # Create at elevenlabs.io if using elevenlabs TTS engine
+# ELEVENLABS_API_KEY is set above in API Keys section
 
 # ─── P4: Agent ─────────────────────────────────────────────────────────────────
 OPENCLAW_URL=http://localhost:8080