feat: add Gallery TUI for interactive configuration and generation

- Implemented a terminal user interface (TUI) for configuring the gallery generator using Textual.
- Included functionality to manage sources with add/remove
- Integrated a log pane to display generation output from subprocess calls.
- Implemented save functionality to persist configuration changes.

pyproject.toml

@@ -37,7 +37,9 @@ dependencies = [
     "Jinja2>=3.0.0",
     "PyYAML>=5.0",
     "argcomplete>=3.0",
+    "platformdirs>=3.0",
     "pytest",
+    "textual>=0.50",
 ]
 
 [project.optional-dependencies]
@@ -66,4 +68,4 @@ line_length = 120
 
 [tool.flake8]
 max-line-length = 120
-extend-ignore = ["E203", "W503"]
+extend-ignore = ["E203", "W503"]