feat(sync): Phase 4 - dynamic subscriptions

- Add SubscriptionManager for per-connection tracking
- Trigger subscription updates on new repo/PR events
- Implement consolidation when filter count > 150

1 files changed, 30 insertions, 1 deletions

diff --git a/src/sync/manager.rs b/src/sync/manager.rs
index 1f70f42..f594454 100644
--- a/src/sync/manager.rs
+++ b/src/sync/manager.rs
@@ -15,6 +15,14 @@
 //! - Health tracking with exponential backoff
 //! - Dead relay detection after 24h of failures
 //! - Startup jitter to prevent thundering herd
+//!
+//! ## Phase 4 Features
+//!
+//! - Dynamic subscription updates handled per-connection
+//! - Each connection manages its own SubscriptionManager
+//! - Announcements trigger Layer 2 subscriptions
+//! - PRs/Issues trigger Layer 3 subscriptions
+//! - Consolidation when filter count exceeds 150
 
 use std::collections::HashSet;
 use std::sync::Arc;
@@ -225,17 +233,38 @@ impl SyncManager {
     }
 
     /// Process a single synced event
+    ///
+    /// Events are validated through the write policy and stored if accepted.
+    /// Dynamic subscription updates are handled by each connection's SubscriptionManager.
     async fn process_event(&self, synced_event: SyncedEvent) {
         let event = &synced_event.event;
         let event_id = event.id.to_hex();
+        let kind = event.kind.as_u16();
 
         tracing::debug!(
             "Processing synced event {} (kind {}) from {}",
             event_id,
-            event.kind.as_u16(),
+            kind,
             synced_event.source_url
         );
 
+        // Log subscription-relevant events for debugging
+        match kind {
+            30617 | 30618 => {
+                tracing::debug!(
+                    "Received announcement {} - connection will add Layer 2 subscription",
+                    event_id
+                );
+            }
+            1617 | 1618 | 1619 | 1621 | 1622 => {
+                tracing::debug!(
+                    "Received PR/Issue {} - connection will add Layer 3 subscription",
+                    event_id
+                );
+            }
+            _ => {}
+        }
+
         // Validate through write policy using SYNC_SOURCE_ADDR
         let result = self.write_policy.admit_event(event, &SYNC_SOURCE_ADDR).await;