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/collectors/systemd.rs

@@ -32,7 +32,7 @@ struct ServiceCacheState {
     nginx_site_metrics: Vec<Metric>,
     /// Last time nginx sites were checked
     last_nginx_check_time: Option<Instant>,
-    /// How often to check nginx site latency (30 seconds)
+    /// How often to check nginx site latency (configurable)
     nginx_check_interval_seconds: u64,
 }
 
@@ -54,7 +54,7 @@ impl SystemdCollector {
                 discovery_interval_seconds: config.interval_seconds,
                 nginx_site_metrics: Vec::new(),
                 last_nginx_check_time: None,
-                nginx_check_interval_seconds: 30, // 30 seconds for nginx sites
+                nginx_check_interval_seconds: config.nginx_check_interval_seconds,
             }),
             config,
         }
@@ -615,10 +615,10 @@ impl SystemdCollector {
 
         let start = Instant::now();
 
-        // Create HTTP client with timeouts (similar to legacy implementation)
+        // Create HTTP client with timeouts from configuration
         let client = reqwest::blocking::Client::builder()
-            .timeout(Duration::from_secs(10))
-            .connect_timeout(Duration::from_secs(10))
+            .timeout(Duration::from_secs(self.config.http_timeout_seconds))
+            .connect_timeout(Duration::from_secs(self.config.http_connect_timeout_seconds))
             .redirect(reqwest::redirect::Policy::limited(10))
             .build()?;