fix(types): resolve pyright errors introduced in #269 changes

- manifest.py: remove unused load_bottle_chain_from_dir import
- manifest_extends.py: drop redundant ManifestEgressRoute annotation
- test_cli_start_selector.py: remove unused call import
- test_cli_tui.py: move Optional/constants to top, annotate FakeScreen,
  remove unused curses import
- test_manifest_bottle_merge.py: add type args to dict, annotate **kwargs

bot_bottle/manifest_extends.py

@@ -48,7 +48,7 @@ def _merge_two_bottles_runtime(base: "ManifestBottle", override: "ManifestBottle
         for n in merged_repos_names
     )
 
-    merged_routes: tuple[ManifestEgressRoute, ...] = base.egress.routes + override.egress.routes
+    merged_routes = base.egress.routes + override.egress.routes
     merged_egress = ManifestEgressConfig(routes=merged_routes, Log=override.egress.Log)
 
     return ManifestBottle(