Update to v0.1.18 with per-collector intervals and tmux check

- Implement per-collector interval timing respecting NixOS config
- Remove all hardcoded timeout/interval values and make configurable
- Add tmux session requirement check for TUI mode (bypassed for headless)
- Update agent to send config hash in Build field instead of nixos version
- Add nginx check interval, HTTP timeouts, and ZMQ transmission interval configs
- Update NixOS configuration with new configurable values

Breaking changes:
- Build field now shows nix store config hash (8 chars) instead of nixos version
- All intervals now follow individual collector configuration instead of global

New configuration fields:
- systemd.nginx_check_interval_seconds
- systemd.http_timeout_seconds
- systemd.http_connect_timeout_seconds
- zmq.transmission_interval_seconds

agent/src/config/mod.rs

@@ -27,6 +27,7 @@ pub struct ZmqConfig {
     pub bind_address: String,
     pub timeout_ms: u64,
     pub heartbeat_interval_ms: u64,
+    pub transmission_interval_seconds: u64,
 }
 
 /// Collector configuration
@@ -104,6 +105,9 @@ pub struct SystemdConfig {
     pub memory_critical_mb: f32,
     pub service_directories: std::collections::HashMap<String, Vec<String>>,
     pub host_user_mapping: String,
+    pub nginx_check_interval_seconds: u64,
+    pub http_timeout_seconds: u64,
+    pub http_connect_timeout_seconds: u64,
 }