fix: always emit phase events based on tempo timing

Previously, phase detection required commit_reveal_enabled=true.
This broke mechanism weights which always use commit-reveal.

Now phases are calculated based on tempo timing regardless of
the CommitRevealWeightsEnabled subnet parameter:
- Evaluation: 0% - 75% of epoch
- CommitWindow: 75% - 87.5% of epoch
- RevealWindow: 87.5% - 100% of epoch

This ensures CommitWindowOpen and RevealWindowOpen events
fire correctly for mechanism weight submission.

Author: EchoBT

src/blocks/epoch_tracker.rs

@@ -147,21 +147,26 @@ impl EpochTracker {
         }
     }
 
-    /// Determine the current phase based on block position
+    /// Determine the current phase based on block position in epoch
+    /// 
+    /// Always calculates phase based on tempo timing, regardless of commit_reveal_enabled.
+    /// This ensures mechanism weights (which always use commit-reveal) work correctly.
+    /// 
+    /// Phases:
+    /// - Evaluation: 0% - 75% of epoch
+    /// - CommitWindow: 75% - 87.5% of epoch  
+    /// - RevealWindow: 87.5% - 100% of epoch
     fn determine_phase(&self, current_block: u64, epoch_start_block: u64) -> EpochPhase {
-        if !self.commit_reveal_enabled {
+        if self.tempo == 0 {
             return EpochPhase::Evaluation;
         }
 
         let blocks_into_epoch = current_block.saturating_sub(epoch_start_block);
 
-        // Bittensor commit-reveal windows:
-        // - Commit window: blocks before reveal window
-        // - Reveal window: last portion of epoch
-        // The exact timing depends on subnet parameters
-
-        // Default: last 25% of epoch is commit/reveal
-        // Last 12.5% is reveal, 12.5% before that is commit
+        // Bittensor commit-reveal windows based on tempo:
+        // - Last 12.5% is reveal window
+        // - 12.5% before that is commit window
+        // - First 75% is evaluation
         let reveal_start = (self.tempo * 7) / 8; // 87.5%
         let commit_start = (self.tempo * 3) / 4; // 75%
 
@@ -260,7 +265,7 @@ mod tests {
         let mut tracker = EpochTracker {
             netuid: 1,
             tempo: 360,
-            commit_reveal_enabled: false,
+            commit_reveal_enabled: false, // Phases still work even if this is false
             reveal_period_epochs: 1,
             last_epoch_number: 0,
         };
@@ -278,4 +283,29 @@ mod tests {
         // No transition at block 400 (same epoch)
         assert!(tracker.check_epoch_transition(400).is_none());
     }
+
+    #[test]
+    fn test_phases_work_regardless_of_commit_reveal_enabled() {
+        // Even with commit_reveal_enabled = false, phases should be calculated
+        // This is important for mechanism weights which always use commit-reveal
+        let tracker = EpochTracker {
+            netuid: 1,
+            tempo: 360,
+            commit_reveal_enabled: false,
+            reveal_period_epochs: 1,
+            last_epoch_number: 0,
+        };
+
+        // Block 100 - evaluation phase
+        let info = tracker.get_epoch_info(100);
+        assert_eq!(info.phase, EpochPhase::Evaluation);
+
+        // Block 270 - commit window (75% of 360)
+        let info = tracker.get_epoch_info(270);
+        assert_eq!(info.phase, EpochPhase::CommitWindow);
+
+        // Block 315 - reveal window (87.5% of 360)
+        let info = tracker.get_epoch_info(315);
+        assert_eq!(info.phase, EpochPhase::RevealWindow);
+    }
 }