tlc: Sprint 3 C4 — Panel::set_path resolves relative paths

Previously, Panel::set_path() would pass the input path straight to
read_directory(). A relative path like 'sub' would fail because
read_directory tries to stat it relative to wherever, not relative
to the user's current working directory.

Implementation:
  Panel::set_path() now checks if p.is_relative() and, if so,
  joins it onto std::env::current_dir() before reading. Absolute
  paths pass through unchanged. Falls back to the raw path if
  current_dir() fails (process has no cwd).

Tests (1 new in panel::tests):
  - set_path_resolves_relative_against_cwd

Total: 1272 passing (was 1271; +1 new).

local/recipes/tui/tlc/source/src/filemanager/panel.rs

@@ -694,14 +694,23 @@ impl Panel {
         Ok(p)
     }
 
-    /// Set the panel's path to `p` and re-read the directory.
-    /// Used by Find/Tree/Hotlist dialogs to navigate the active
-    /// panel to a chosen location.
+    /// Set the panel's path to `p` and re-read the directory. Used
+    /// by Find/Tree/Hotlist dialogs to navigate the active panel to
+    /// a chosen location. Relative paths are resolved against the
+    /// current working directory before navigation.
     pub fn set_path(&mut self, p: &Path) -> Result<()> {
-        if p == self.path {
+        let resolved = if p.is_relative() {
+            match std::env::current_dir() {
+                Ok(cwd) => cwd.join(p),
+                Err(_) => p.to_path_buf(),
+            }
+        } else {
+            p.to_path_buf()
+        };
+        if resolved == self.path {
             return Ok(());
         }
-        self.read_directory(p)
+        self.read_directory(&resolved)
     }
 
     /// Re-read the current directory.
@@ -1103,6 +1112,23 @@ mod tests {
         let _ = fs::remove_dir_all(&dir);
     }
 
+    #[test]
+    fn set_path_resolves_relative_against_cwd() {
+        let dir = std::env::temp_dir().join("tlc-panel-relative-test");
+        let sub = dir.join("sub");
+        let _ = fs::create_dir_all(&sub);
+        fs::write(sub.join("x.txt"), b"x").unwrap();
+        let mut p = Panel::new(&dir, &empty_cfg()).unwrap();
+        // Simulate cwd = dir by chdir; restore on drop.
+        let prev_cwd = std::env::current_dir().unwrap();
+        std::env::set_current_dir(&dir).unwrap();
+        let relative = std::path::PathBuf::from("sub");
+        p.set_path(&relative).unwrap();
+        assert_eq!(p.path(), sub.canonicalize().unwrap_or(sub));
+        std::env::set_current_dir(&prev_cwd).unwrap();
+        let _ = fs::remove_dir_all(&dir);
+    }
+
     #[test]
     fn cursor_movement() {
         let dir = std::env::temp_dir().join("tlc-panel-cursor-test");