Add unified process_newly_available_git_data function

Implement the unified function that handles all post-git-data-available
processing, regardless of how data arrived (git push or purgatory sync).

This function:
- Discovers satisfiable events from purgatory (state and PR events)
- Syncs OIDs to authorized owner repos
- Aligns refs and sets HEAD
- Saves events to database
- Notifies WebSocket subscribers
- Removes from purgatory

New additions:
- ProcessResult struct for tracking processing outcomes
- process_newly_available_git_data async function in src/git/sync.rs
- Helper functions: extract_identifier_from_repo_path, extract_identifier_from_pr_event
- Purgatory::find_prs_for_identifier method for PR event discovery
- Unit tests for all helper functions

Also fixes:
- Simplified extract_domain to avoid url crate dependency
- Removed unused imports in sync/loop.rs

1 files changed, 1 insertions, 1 deletions

diff --git a/src/purgatory/sync/loop.rs b/src/purgatory/sync/loop.rs
index aaf1300..ebca766 100644
--- a/src/purgatory/sync/loop.rs
+++ b/src/purgatory/sync/loop.rs
@@ -12,7 +12,7 @@
 use std::sync::Arc;
 use std::time::Duration;
 use tokio::task::JoinHandle;
-use tracing::{debug, info, warn};
+use tracing::{debug, info};
 
 use crate::purgatory::Purgatory;