Pane(feat[set_title]): Add set_title() method and pane_title support

why: tmux supports select-pane -T and #{pane_title} (since 2.6).
tmuxinator uses this for named panes. libtmux had no wrapper and
pane_title was commented out of formats.py.
what:
- Uncomment pane_title in formats.py PANE_FORMATS list
- Add pane_title field to neo.Obj dataclass
- Add Pane.set_title() method using select-pane -T
- Add Pane.title property alias for pane_title
- Add tests for set_title with plain and special characters

Author: tony

src/libtmux/formats.py

@@ -67,7 +67,7 @@
     "pane_index",
     "pane_width",
     "pane_height",
-    # "pane_title",  # removed in 3.1+
+    "pane_title",
     "pane_id",
     "pane_active",
     "pane_dead",

src/libtmux/neo.py

@@ -103,6 +103,7 @@ class Obj:
     pane_start_command: str | None = None
     pane_start_path: str | None = None
     pane_tabs: str | None = None
+    pane_title: str | None = None
     pane_top: str | None = None
     pane_tty: str | None = None
     pane_width: str | None = None

src/libtmux/pane.py

@@ -831,6 +831,32 @@ def set_height(self, height: int) -> Pane:
         self.resize(height=height)
         return self
 
+    def set_title(self, title: str) -> Pane:
+        """Set pane title via ``select-pane -T``.
+
+        Parameters
+        ----------
+        title : str
+            Title to set for the pane.
+
+        Returns
+        -------
+        :class:`Pane`
+
+        Examples
+        --------
+        >>> pane.set_title('my-title')
+        Pane(...)
+
+        >>> pane.pane_title
+        'my-title'
+        """
+        proc = self.cmd("select-pane", "-T", title)
+        if proc.stderr:
+            raise exc.LibTmuxException(proc.stderr)
+        self.refresh()
+        return self
+
     def enter(self) -> Pane:
         """Send carriage return to pane.
 
@@ -913,6 +939,18 @@ def width(self) -> str | None:
         """
         return self.pane_width
 
+    @property
+    def title(self) -> str | None:
+        """Alias for :attr:`pane_title`.
+
+        >>> pane.set_title('test-alias')
+        Pane(...)
+
+        >>> pane.title == pane.pane_title
+        True
+        """
+        return self.pane_title
+
     @property
     def at_top(self) -> bool:
         """Typed, converted wrapper around :attr:`Pane.pane_at_top`.

tests/test_pane.py

@@ -303,6 +303,25 @@ def test_split_pane_size(session: Session) -> None:
     assert new_pane.at_right
 
 
+def test_set_title(session: Session) -> None:
+    """Test Pane.set_title() sets pane title."""
+    window = session.active_window
+    pane = window.active_pane
+    assert pane is not None
+    result = pane.set_title("test-title")
+    assert result == pane  # returns self for chaining
+    assert pane.pane_title == "test-title"
+    assert pane.title == "test-title"
+
+
+def test_set_title_special_characters(session: Session) -> None:
+    """Test Pane.set_title() with spaces and unicode."""
+    pane = session.active_window.active_pane
+    assert pane is not None
+    pane.set_title("my pane title")
+    assert pane.pane_title == "my pane title"
+
+
 def test_pane_context_manager(session: Session) -> None:
     """Test Pane context manager functionality."""
     window = session.new_window()