Refactor supervisor to use environment variables and simplify binary

- Created scripts/generate_secret.sh to generate supervisor secrets
- Added .env.example with all configuration options
- Created scripts/environment.sh to load env vars from .env
- Updated scripts/run.sh to use env vars and pass as flags
- Simplified supervisor binary:
  - Removed bootstrap-admin-key and config file support
  - Made admin-secret required
  - Minimal output (only URLs)
  - Clean startup with no verbose logging
- Updated .gitignore for .env and log files

.env.example

@@ -0,0 +1,19 @@
+# Hero Supervisor Configuration
+
+# Redis connection URL
+REDIS_URL=redis://127.0.0.1:6379
+
+# OpenRPC Server Configuration
+BIND_ADDRESS=127.0.0.1
+PORT=3030
+
+# Authentication Secrets (generate with: ./scripts/generate_secret.sh)
+# At least one admin secret is required
+ADMIN_SECRETS=your_admin_secret_here
+
+# Optional: Additional secrets for different access levels
+# USER_SECRETS=user_secret_1,user_secret_2
+# REGISTER_SECRETS=register_secret_1
+
+# Optional: Mycelium network URL (requires mycelium feature)
+# MYCELIUM_URL=http://127.0.0.1:8989