fix(graph): stop filtering phase 2 commits by current user email

The two-phase refresh unconditionally passed current_user_email as the
author_filter for phase 2, so only the current user's commits loaded
after the first 100. This left other authors' commits missing, preventing
branch lanes from converging and causing the graph to grow extremely wide.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: noahclarksonkendons

crates/rgitui_git/src/project/refresh.rs

@@ -601,7 +601,6 @@ impl GitProject {
                 .await?;
 
             let needs_more = data.has_more_commits && first_batch < commit_limit;
-            let user_email_for_commits = data.current_user_email.clone();
             let branch_tips: Vec<(git2::Oid, bool, String)> = data
                 .branches
                 .iter()
@@ -630,7 +629,6 @@ impl GitProject {
             if needs_more {
                 let remaining = commit_limit - first_batch;
                 let repo_path_p2 = repo_path.clone();
-                let user_email_p2 = user_email_for_commits.clone();
                 let (more_commits, has_more) = cx
                     .background_executor()
                     .spawn(async move {
@@ -640,7 +638,7 @@ impl GitProject {
                             remaining,
                             &branch_tips,
                             &tag_tips,
-                            user_email_p2.as_deref(),
+                            None,
                         )
                     })
                     .await?;