fix: Correct provider type seeding and add missing env vars for all channels

- Fix seedManagedData() hardcoding openai_compat for all non-Anthropic providers;
  now uses resolveProviderType() mapping to correct store constants (gemini_native,
  minimax_native, etc.) — fixes model listing in web UI for Gemini
- Rename GOCLAW_FEISHU_* env vars to GOCLAW_LARK_* (Lark is the global brand)
- Add WhatsApp env override (GOCLAW_WHATSAPP_BRIDGE_URL) and auto-enable
- Add missing env vars to docker-compose.yml (Cohere, Perplexity, Lark, Zalo, WhatsApp)
- Update .env.example with all providers/channels, remove unnecessary GOCLAW_PROVIDER
- Add Cohere and Perplexity to prepare-env.sh provider detection

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

.env.example

@@ -4,12 +4,20 @@
 # Required: at least one LLM provider API key.
 # Auto-generated by prepare-env.sh: GOCLAW_GATEWAY_TOKEN, GOCLAW_ENCRYPTION_KEY.
 
-# --- LLM Provider (at least one required) ---
-GOCLAW_PROVIDER=
-GOCLAW_MODEL=
+# --- LLM Provider (at least one API key required) ---
+# Provider is auto-detected from API keys. Default model is chosen per provider.
+# GOCLAW_MODEL=                  # Optional: override default model
 GOCLAW_OPENROUTER_API_KEY=
 GOCLAW_ANTHROPIC_API_KEY=
+GOCLAW_OPENAI_API_KEY=
 GOCLAW_MINIMAX_API_KEY=
+GOCLAW_GROQ_API_KEY=
+GOCLAW_DEEPSEEK_API_KEY=
+GOCLAW_GEMINI_API_KEY=
+GOCLAW_MISTRAL_API_KEY=
+GOCLAW_XAI_API_KEY=
+GOCLAW_COHERE_API_KEY=
+GOCLAW_PERPLEXITY_API_KEY=
 
 # --- Gateway ---
 GOCLAW_GATEWAY_TOKEN=
@@ -18,6 +26,12 @@ GOCLAW_ENCRYPTION_KEY=
 # --- Channels (optional) ---
 GOCLAW_TELEGRAM_TOKEN=
 GOCLAW_DISCORD_TOKEN=
+GOCLAW_LARK_APP_ID=
+GOCLAW_LARK_APP_SECRET=
+# GOCLAW_LARK_ENCRYPT_KEY=
+# GOCLAW_LARK_VERIFICATION_TOKEN=
+GOCLAW_ZALO_TOKEN=
+# GOCLAW_WHATSAPP_BRIDGE_URL=
 
 # --- Database (only for non-Docker deployments) ---
 # Docker Compose auto-builds this from POSTGRES_USER/PASSWORD/DB.