feat(llm): direct Claude Haiku 4.5 backend with prompt caching

Adds a parallel LLM backend that bypasses OpenClaw and talks to
Anthropic Messages API directly. Selected via LLM_BACKEND=claude in
.env; default remains openclaw so nothing breaks for existing setup.

Why: OpenClaw gateway adds 500-1000ms overhead on every turn (auth,
memory fetch, routing). Direct Haiku 4.5 + prompt caching = faster
first token and -90% cost on cached chunks.

- satellite/llm_claude.py — Anthropic SDK streaming client, prompt
  caching on system prompt and all-but-last-2 history messages, per
  agent+date JSON history in HISTORY_DIR, reset_history() for the
  'сбрось' command, per-agent system prompts (Cosmo / Люся), fallback
  to error event if SDK/key missing.
- satellite/llm.py — dispatches to ask_claude_stream when backend=claude,
  exports LLM_BACKEND so modes.py can route reset too.
- satellite/modes.py — _handle_reset calls reset_history when backend
  is claude, keeps /new POST for openclaw.
- requirements.txt — anthropic >= 0.50.0
- .env.example — LLM_BACKEND, ANTHROPIC_API_KEY, ANTHROPIC_MODEL,
  HISTORY_DIR, MAX_HISTORY, HTTPS_PROXY block for non-RU egress.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.env.example

@@ -59,3 +59,22 @@ VOICE_API_KEY=your_voice_api_key_here
 # голос ассистента проигрывается на планшете через ElevenLabs proxy,
 # локальный mpv/speak пропускается. false = говорим локально как раньше.
 TABLET_TTS_ENABLED=true
+
+# ——————————————————————————————————————————————
+# LLM backend
+# openclaw (дефолт) — существующий путь через gateway с памятью на сервере
+# claude             — прямой вызов Anthropic Haiku 4.5 с локальной историей
+#                       и prompt caching (быстрее + дешевле, но без tools)
+LLM_BACKEND=openclaw
+
+# Для LLM_BACKEND=claude:
+ANTHROPIC_API_KEY=your_anthropic_key_here
+ANTHROPIC_MODEL=claude-haiku-4-5
+HISTORY_DIR=data/history    # куда сохранять JSON истории per-agent per-date
+MAX_HISTORY=40              # лимит сообщений в истории
+
+# Egress proxy для non-RU сервисов (Anthropic, Groq, OpenAI).
+# httpx и requests подхватывают автоматически. Пусто = прямой выход.
+HTTPS_PROXY=http://192.168.31.103:8888
+HTTP_PROXY=http://192.168.31.103:8888
+NO_PROXY=localhost,127.0.0.1,192.168.31.0/24