feat(nightwatch): add active hours window for drift evaluation

Nightwatch evaluate() is now gated by active_start_hour / active_end_hour
in NightwatchConfig. Defaults to 0-24 (always active) for backwards
compatibility. Supports wrap-around past midnight (e.g. 22-06).

This allows the orchestrator to run nightwatch only during off-peak hours,
e.g. 2am-6am, reducing noise during active development.

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

Author: AlexMikhalev

crates/terraphim_orchestrator/src/config.rs

@@ -122,6 +122,12 @@ pub struct NightwatchConfig {
     /// Drift percentage threshold for Critical correction.
     #[serde(default = "default_critical_threshold")]
     pub critical_threshold: f64,
+    /// Hour (0-23) when nightwatch evaluation starts. Default: 0 (midnight).
+    #[serde(default)]
+    pub active_start_hour: u8,
+    /// Hour (0-23) when nightwatch evaluation ends. Default: 24 (always active).
+    #[serde(default = "default_active_end_hour")]
+    pub active_end_hour: u8,
 }
 
 impl Default for NightwatchConfig {
@@ -132,6 +138,8 @@ impl Default for NightwatchConfig {
             moderate_threshold: default_moderate_threshold(),
             severe_threshold: default_severe_threshold(),
             critical_threshold: default_critical_threshold(),
+            active_start_hour: 0,
+            active_end_hour: default_active_end_hour(),
         }
     }
 }
@@ -151,6 +159,9 @@ fn default_severe_threshold() -> f64 {
 fn default_critical_threshold() -> f64 {
     0.70
 }
+fn default_active_end_hour() -> u8 {
+    24
+}
 
 /// Compound review settings.
 #[derive(Debug, Clone, Serialize, Deserialize)]

crates/terraphim_orchestrator/src/lib.rs

@@ -62,6 +62,7 @@ pub use nightwatch::{
 pub use persona::{MetapromptRenderError, MetapromptRenderer, PersonaRegistry};
 pub use scheduler::{ScheduleEvent, TimeScheduler};
 
+use chrono::Timelike;
 use std::collections::HashMap;
 use std::path::Path;
 use std::time::{Duration, Instant};
@@ -597,8 +598,18 @@ impl AgentOrchestrator {
         // 4. Drain output events to nightwatch
         self.drain_output_events();
 
-        // 5. Evaluate nightwatch drift
-        self.nightwatch.evaluate();
+        // 5. Evaluate nightwatch drift (only during active hours)
+        let nw_cfg = &self.config.nightwatch;
+        let current_hour = chrono::Local::now().hour() as u8;
+        let in_window = if nw_cfg.active_start_hour <= nw_cfg.active_end_hour {
+            current_hour >= nw_cfg.active_start_hour && current_hour < nw_cfg.active_end_hour
+        } else {
+            // Wraps past midnight, e.g. start=22 end=6
+            current_hour >= nw_cfg.active_start_hour || current_hour < nw_cfg.active_end_hour
+        };
+        if in_window {
+            self.nightwatch.evaluate();
+        }
 
         // 6. Sweep expired handoff buffer entries
         let swept = self.handoff_buffer.sweep_expired();