Add tree-based file browser for snapshot contents

Replace flat file list with a Tree widget that shows directory
structure. Strips remote path prefix to show relative paths only.
Folders shown in bold with trailing /, sorted dirs-first.

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

tui/gniza.tcss

@@ -245,6 +245,35 @@ SelectionList {
     margin: 0;
 }
 
+/* Snapshot browser */
+#snapshot-browser {
+    width: 80%;
+    height: 80%;
+    padding: 1;
+    background: $panel;
+    border: thick $accent;
+}
+
+#sb-title {
+    text-style: bold;
+    color: #00cc00;
+    margin: 0 0 1 0;
+}
+
+#sb-tree {
+    height: 1fr;
+    border: round $accent;
+}
+
+#sb-buttons {
+    height: auto;
+    margin: 1 0 0 0;
+}
+
+#sb-buttons Button {
+    margin: 0 1 0 0;
+}
+
 /* Log viewer */
 #log-viewer {
     height: 1fr;

tui/screens/snapshots.py

@@ -1,3 +1,5 @@
+import re
+
 from textual.app import ComposeResult
 from textual.screen import Screen
 from textual.widgets import Header, Footer, Static, Button, Select, DataTable
@@ -6,7 +8,7 @@ from textual import work
 
 from tui.config import list_conf_dir
 from tui.backend import run_cli
-from tui.widgets import OperationLog
+from tui.widgets import SnapshotBrowser
 
 
 class SnapshotsScreen(Screen):
@@ -91,17 +93,33 @@ class SnapshotsScreen(Screen):
             return
         target = str(target_sel.value)
         remote = str(remote_sel.value)
-        log_screen = OperationLog(f"Files: {target}/{snapshot}", show_spinner=False)
-        self.app.push_screen(log_screen)
+
+        self.notify("Loading files...")
         rc, stdout, stderr = await run_cli(
             "snapshots", "browse", f"--target={target}", f"--remote={remote}", f"--snapshot={snapshot}"
         )
-        if stdout:
-            log_screen.write(stdout)
-        if stderr:
-            log_screen.write(stderr)
-        if not stdout and not stderr:
-            log_screen.write("No files found.")
+
+        # Parse file list, strip remote prefix to get relative paths
+        # Paths look like: /remote/base/.../snapshots/<timestamp>/etc/foo.conf
+        # We want everything after the snapshot timestamp directory
+        files = []
+        pattern = re.compile(re.escape(snapshot) + r"/(.*)")
+        for line in (stdout or "").splitlines():
+            line = line.strip()
+            if not line:
+                continue
+            m = pattern.search(line)
+            if m:
+                files.append(m.group(1))
+            else:
+                files.append(line)
+
+        if not files:
+            self.notify("No files found in snapshot", severity="warning")
+            return
+
+        browser = SnapshotBrowser(f"{target} / {snapshot}", files)
+        self.app.push_screen(browser)
 
     def action_go_back(self) -> None:
         self.app.pop_screen()

tui/widgets/__init__.py

@@ -2,3 +2,4 @@ from tui.widgets.folder_picker import FolderPicker
 from tui.widgets.file_picker import FilePicker
 from tui.widgets.confirm_dialog import ConfirmDialog
 from tui.widgets.operation_log import OperationLog
+from tui.widgets.snapshot_browser import SnapshotBrowser

tui/widgets/snapshot_browser.py

@@ -0,0 +1,64 @@
+from __future__ import annotations
+
+from pathlib import PurePosixPath
+from textual.app import ComposeResult
+from textual.screen import ModalScreen
+from textual.widgets import Tree, Static, Button
+from textual.containers import Vertical, Horizontal
+
+
+class SnapshotBrowser(ModalScreen[None]):
+    """Modal file browser for remote snapshot contents."""
+
+    BINDINGS = [("escape", "close", "Close")]
+
+    def __init__(self, title: str, file_list: list[str]):
+        super().__init__()
+        self._title = title
+        self._file_list = file_list
+
+    def compose(self) -> ComposeResult:
+        with Vertical(id="snapshot-browser"):
+            yield Static(self._title, id="sb-title")
+            yield Tree("snapshot", id="sb-tree")
+            with Horizontal(id="sb-buttons"):
+                yield Button("Close", variant="primary", id="sb-close")
+
+    def on_mount(self) -> None:
+        tree = self.query_one("#sb-tree", Tree)
+        tree.root.expand()
+        self._build_tree(tree)
+
+    def _build_tree(self, tree: Tree) -> None:
+        # Build a nested dict from file paths
+        root: dict = {}
+        for filepath in self._file_list:
+            filepath = filepath.strip()
+            if not filepath:
+                continue
+            parts = PurePosixPath(filepath).parts
+            node = root
+            for part in parts:
+                if part not in node:
+                    node[part] = {}
+                node = node[part]
+
+        # Add to tree widget recursively
+        self._add_nodes(tree.root, root)
+        tree.root.expand_all()
+
+    def _add_nodes(self, parent, structure: dict) -> None:
+        # Sort: directories first, then files
+        dirs = sorted(k for k, v in structure.items() if v)
+        files = sorted(k for k, v in structure.items() if not v)
+        for name in dirs:
+            branch = parent.add(f"[bold]{name}/[/bold]")
+            self._add_nodes(branch, structure[name])
+        for name in files:
+            parent.add_leaf(name)
+
+    def on_button_pressed(self, event: Button.Pressed) -> None:
+        self.dismiss(None)
+
+    def action_close(self) -> None:
+        self.dismiss(None)