fix: replace repo_sync_index wiring with purgatory announcement sync timer

Instead of threading repo_sync_index through PolicyContext/builder.rs/main.rs
to handle user-submitted purgatory announcements, add a simple background
timer (run_purgatory_announcement_sync, every 5s) that scans the purgatory
for announcement entries and registers them in repo_sync_index as StateOnly.

This is simpler and covers both flows:
- Sync-path announcements: inline registration still happens during event
  processing (sync/mod.rs:1839+), timer provides a safety net
- User-submitted announcements: SelfSubscriber never sees them (rejected
  from DB), timer is the primary registration path

The timer calls sync_purgatory_announcements_to_index() which:
1. Snapshots purgatory via new announcements_for_sync() public method
2. Or_inserts StateOnly entries (never downgrades Full entries)
3. Detects newly added relay URLs and calls handle_new_sync_filters to
   connect and subscribe - fixing the failing test that expected relay
   discovery from a user-submitted purgatory announcement

Removes: repo_sync_index field from PolicyContext, set/get_repo_sync_index
methods, set_repo_sync_index on Nip34WritePolicy, wiring in main.rs, and
the inline AcceptPurgatory registration block in builder.rs.

1 files changed, 1 insertions, 53 deletions

diff --git a/src/nostr/builder.rs b/src/nostr/builder.rs
index 8d1e461..c2d4939 100644
--- a/src/nostr/builder.rs
+++ b/src/nostr/builder.rs
@@ -17,7 +17,7 @@ use crate::nostr::policy::{
     AnnouncementPolicy, AnnouncementResult, PolicyContext, PrEventPolicy, ReferenceResult,
     RelatedEventPolicy, StatePolicy, StateResult,
 };
-use crate::sync::{RepoSyncIndex, RepoSyncNeeds, SyncLevel};
+
 
 /// Type alias for the shared database used by the relay
 pub type SharedDatabase = Arc<dyn NostrDatabase>;
@@ -99,14 +99,6 @@ impl Nip34WritePolicy {
         self.ctx.set_local_relay(relay);
     }
 
-    /// Set the repo sync index so that user-submitted purgatory announcements can
-    /// be registered for state event sync immediately.
-    ///
-    /// This must be called after SyncManager is created.
-    pub fn set_repo_sync_index(&self, index: RepoSyncIndex) {
-        self.ctx.set_repo_sync_index(index);
-    }
-
     /// Handle repository announcement event
     async fn handle_announcement(&self, event: &Event) -> WritePolicyResult {
         let event_id_str = event.id.to_bech32().unwrap_or_else(|_| event.id.to_hex());
@@ -156,50 +148,6 @@ impl Nip34WritePolicy {
                             event_id_str
                         );
 
-                        // Register repo in repo_sync_index with StateOnly level so that
-                        // state event sync starts promptly via the next batch EOSE recompute.
-                        // This handles user-submitted purgatory announcements - the SelfSubscriber
-                        // only sees DB events, so it won't pick these up automatically.
-                        if let Some(repo_sync_index) = self.ctx.get_repo_sync_index() {
-                            if let Ok(announcement) =
-                                RepositoryAnnouncement::from_event(event.clone())
-                            {
-                                use std::collections::HashSet;
-                                let repo_id = format!(
-                                    "30617:{}:{}",
-                                    event.pubkey,
-                                    announcement.identifier
-                                );
-
-                                // Extract relay URLs from the announcement event tags
-                                let relays: HashSet<String> = event
-                                    .tags
-                                    .iter()
-                                    .flat_map(|tag| {
-                                        let tag_vec = tag.as_slice();
-                                        if !tag_vec.is_empty() && tag_vec[0] == "relays" {
-                                            tag_vec[1..].iter().map(|s| s.to_string()).collect::<Vec<_>>()
-                                        } else {
-                                            vec![]
-                                        }
-                                    })
-                                    .collect();
-
-                                let mut index = repo_sync_index.write().await;
-                                index.entry(repo_id.clone()).or_insert_with(|| RepoSyncNeeds {
-                                    relays,
-                                    root_events: HashSet::new(),
-                                    sync_level: SyncLevel::StateOnly,
-                                });
-                                drop(index);
-
-                                tracing::debug!(
-                                    repo_id = %repo_id,
-                                    "Registered purgatory announcement in repo_sync_index as StateOnly"
-                                );
-                            }
-                        }
-
                         WritePolicyResult::Reject {
                             status: true, // Client sees OK
                             message: "purgatory: won't be served until git data arrives".into(),