fix: simplify purgatory sync - fix SelfSubscriber sync_level upgrade and negentropy fallback

Three targeted fixes for purgatory announcement sync:

1. SelfSubscriber sync_level upgrade: After or_insert_with in process_batch,
   always set entry.sync_level = SyncLevel::Full so that when a promoted
   announcement is broadcast via notify_event and SelfSubscriber receives it,
   an existing StateOnly entry gets upgraded to Full and PR event subscriptions
   are triggered immediately (not delayed up to 24h).

2. Negentropy fallback filter split: In handle_eose, when falling back from
   negentropy to REQ+EOSE, split batch_repos by SyncLevel and call
   build_sync_level_aware_filters instead of build_layer2_and_layer3_filters.
   Prevents StateOnly (purgatory) repos from getting Layer 2 #a/#A/#q filters
   prematurely, which caused nostr-sdk client deduplication to permanently
   drop PR events after orphan rejection.

3. Recompute sync filters after announcement batch EOSE: Add
   recompute_new_sync_filters_for_relay calls at all three batch-completion
   paths in handle_eose for generic filter (announcement) batches. This
   triggers state-only subscriptions for any purgatory repos registered during
   that batch, fixing the 24h delay before state event sync starts.

4. User-submitted purgatory announcements: Add repo_sync_index field to
   PolicyContext with setter/getter, wire in main.rs after SyncManager
   creation, and register in AcceptPurgatory handler so user-submitted
   announcements get StateOnly sync started immediately.

5. Update archive tests: test_archive_without_state_events_does_not_sync_git
   updated to reflect that StateOnly subscription now proactively fetches
   state events from source relays. test_archive_read_only_creates_bare_repo
   un-ignored as it now works end-to-end.

1 files changed, 7 insertions, 0 deletions

diff --git a/src/main.rs b/src/main.rs
index ab6ede7..ebe05a3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -132,6 +132,13 @@ async fn main() -> Result<()> {
         // Get a reference to the rejected events index for shutdown persistence
         let shutdown_rejected_index = sync_manager.rejected_events_index();
 
+        // Wire repo_sync_index into write policy so user-submitted purgatory announcements
+        // get registered for state event sync immediately (Fix 3).
+        let repo_sync_index = sync_manager.repo_sync_index();
+        relay_with_db
+            .write_policy
+            .set_repo_sync_index(repo_sync_index);
+
         tokio::spawn(async move {
             sync_manager.run().await;
         });