test(git): pin status.showUntrackedFiles in the tests' scratch repositories (#1091)

Five tty7-core tests and two tty7-server conformance checks failed on a
machine with a global `status.showUntrackedFiles=no`: git hid the files
they had just written. PINS (and so pin_repo_config) now carries
`status.showUntrackedFiles=normal`, the worktree tests' temp_repo pins
its repository, and the host conformance suite's git_repo sets the key
itself, since other crates run it.

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

crates/tty7-core/src/core/git/mod.rs

@@ -481,8 +481,9 @@ pub(crate) mod test_support {
     /// have signing on globally. The two line-ending settings are here for the
     /// same reason: Git for Windows ships `core.autocrlf=true` in its *system*
     /// config, so a fixture built with LF and read back is a fixture whose
-    /// bytes depend on which machine ran the test.
-    pub(crate) const PINS: [&str; 10] = [
+    /// bytes depend on which machine ran the test. A developer's
+    /// `status.showUntrackedFiles=no` would hide the files a test just wrote.
+    pub(crate) const PINS: [&str; 12] = [
         "-c",
         "user.name=tty7 test",
         "-c",
@@ -493,6 +494,8 @@ pub(crate) mod test_support {
         "core.autocrlf=false",
         "-c",
         "core.eol=lf",
+        "-c",
+        "status.showUntrackedFiles=normal",
     ];
 
     /// The same settings, written into `<repo>/.git/config`.

crates/tty7-core/src/core/worktree/mod.rs

@@ -452,8 +452,7 @@ mod tests {
     fn temp_repo(name: &str) -> PathBuf {
         let dir = scratch(name);
         sh(&dir, &["git", "init", "-q"]);
-        sh(&dir, &["git", "config", "user.email", "t@t"]);
-        sh(&dir, &["git", "config", "user.name", "t"]);
+        assert!(crate::core::git::test_support::pin_repo_config(&dir));
         std::fs::write(dir.join("a.txt"), "a").unwrap();
         sh(&dir, &["git", "add", "."]);
         sh(&dir, &["git", "commit", "-q", "-m", "init"]);

crates/tty7-core/src/host/conformance.rs

@@ -152,6 +152,12 @@ fn hit_names(hits: &[SearchHit]) -> Vec<&str> {
 
 fn git_repo(h: &dyn Host, dir: &Path) -> Option<()> {
     let out = h.git(dir, &["init", "--quiet"]).ok()?;
+    out.success().then_some(())?;
+    // A developer's `status.showUntrackedFiles=no` would hide the files a
+    // check just wrote.
+    let out = h
+        .git(dir, &["config", "status.showUntrackedFiles", "normal"])
+        .ok()?;
     out.success().then_some(())
 }