Add RealSyncContext implementation for production purgatory sync

Implement the production SyncContext that connects to real systems:

- RealSyncContext struct holding purgatory, database, git_data_path,
  our_domain, and local_relay references

- fetch_repository_data: delegates to git::authorization module

- collect_needed_oids: collects commit hashes from state events
  (branches/tags) and PR events (c-tag) in purgatory

- oid_exists: delegates to git::oid_exists function

- fetch_oids: uses git fetch --depth=1 to retrieve specific OIDs
  from remote servers, running in spawn_blocking for async safety

- process_newly_available_git_data: delegates to the unified function
  in git::sync module for consistent post-git-data processing

- has_pending_events: delegates to purgatory method

- find_target_repo: finds first existing owner repository on disk

- our_domain: returns configured domain for clone URL filtering

This enables the purgatory sync loop to use real database queries,
git operations, and event processing instead of mocks.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/purgatory/sync/mod.rs b/src/purgatory/sync/mod.rs
index be89130..022a556 100644
--- a/src/purgatory/sync/mod.rs
+++ b/src/purgatory/sync/mod.rs
@@ -13,7 +13,7 @@ mod r#loop;
 mod queue;
 mod throttle;
 
-pub use context::{ProcessResult, SyncContext};
+pub use context::{ProcessResult, RealSyncContext, SyncContext};
 pub use functions::{
     get_throttled_domains_with_untried_urls, sync_identifier, sync_identifier_from_url,
     sync_identifier_next_url, ThrottledDomainInfo,