feat: add StatusBar and StreamingStatic widgets

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/ui/widgets.py

@@ -0,0 +1,65 @@
+"""Custom Textual widgets for SneakyCode TUI."""
+
+from __future__ import annotations
+
+from rich.text import Text
+from textual.widgets import Static
+
+
+class StatusBar(Static):
+    """Single-line status bar showing token usage and iteration count."""
+
+    DEFAULT_CSS = """
+    StatusBar {
+        dock: bottom;
+        height: 1;
+        background: $surface;
+        color: $text-muted;
+        padding: 0 2;
+    }
+    """
+
+    def __init__(self) -> None:
+        super().__init__("")
+        self._tokens: int = 0
+        self._budget: int = 0
+        self._iteration: int = 0
+        self._max_iterations: int = 0
+
+    def update_tokens(self, tokens: int, budget: int) -> None:
+        """Update the token usage display."""
+        self._tokens = tokens
+        self._budget = budget
+        self._refresh_display()
+
+    def update_iteration(self, iteration: int, max_iterations: int) -> None:
+        """Update the iteration count display."""
+        self._iteration = iteration
+        self._max_iterations = max_iterations
+        self._refresh_display()
+
+    def _refresh_display(self) -> None:
+        """Rebuild the status bar text."""
+        parts: list[str] = []
+        if self._budget > 0:
+            parts.append(f"Tokens: ~{self._tokens:,} / {self._budget:,}")
+        if self._max_iterations > 0:
+            parts.append(f"Iteration {self._iteration}/{self._max_iterations}")
+        self.update(Text(" │ ".join(parts), style="dim"))
+
+
+class StreamingStatic(Static):
+    """A Static widget that stays mounted but hidden during non-streaming periods.
+
+    During streaming, call show() to make visible and update() with partial content.
+    When streaming ends, call hide() to conceal.
+    """
+
+    def show_streaming(self) -> None:
+        """Make the widget visible for streaming."""
+        self.add_class("visible")
+
+    def hide_streaming(self) -> None:
+        """Hide the widget and clear content."""
+        self.remove_class("visible")
+        self.update("")