Fix push_target remote reuse and non-fatal per-repo errors

- git_mirror: reuse existing push_target remote via remote_set_url
  instead of failing on 'remote already exists' on subsequent cycles
- mirror_cycle: catch per-repo errors instead of propagating with ?
  so one failed clone doesn't abort the remaining 87 repos
- Add PLAN.md with bug tracking checklist

2 files changed, 24 insertions, 5 deletions

diff --git a/src/git_mirror.rs b/src/git_mirror.rs
index 47c0442..6866de3 100644
--- a/src/git_mirror.rs
+++ b/src/git_mirror.rs
@@ -134,7 +134,18 @@ impl GitMirror {
         let repo = git2::Repository::open(repo_path)
             .with_context(|| format!("failed to open bare repo at {:?}", repo_path))?;
 
-        let mut remote = repo.remote("push_target", target_url)?;
+        let remote_name = "push_target";
+
+        match repo.find_remote(remote_name) {
+            Ok(_) => {
+                repo.remote_set_url(remote_name, target_url)?;
+            }
+            Err(_) => {
+                repo.remote(remote_name, target_url)?;
+            }
+        }
+
+        let mut remote = repo.find_remote(remote_name)?;
 
         let mut callbacks = RemoteCallbacks::new();
         callbacks.credentials(|_url, _username, _allowed| git2::Cred::default());
diff --git a/src/main.rs b/src/main.rs
index 494342c..3fcd27b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -190,13 +190,21 @@ async fn mirror_cycle(
             "mirroring to missing servers"
         );
 
-        mirror.mirror_repo_to_servers(db, repo, &missing).await?;
-        nostr_mirror.forward_repo_events(db, repo, servers).await?;
+        if let Err(e) = mirror.mirror_repo_to_servers(db, repo, &missing).await {
+            tracing::error!(identifier = %repo.identifier, error = %e, "git mirror failed for repo, continuing");
+        }
+
+        if let Err(e) = nostr_mirror.forward_repo_events(db, repo, servers).await {
+            tracing::error!(identifier = %repo.identifier, error = %e, "nostr mirror failed for repo, continuing");
+        }
     }
 
-    nostr_mirror
+    if let Err(e) = nostr_mirror
         .sync_all_events(db, &config.npubs, servers)
-        .await?;
+        .await
+    {
+        tracing::error!(error = %e, "event sync failed");
+    }
 
     tracing::info!("mirror cycle complete");
     Ok(())