fix: resolve pylint and pyright linting issues

- Remove .keys() iteration in favor of direct dictionary iteration
- Remove redundant os module reimport in tui.py
- Disable unnecessary-ellipsis rule in pylintrc to avoid conflict with pyright's
  Protocol type requirements

pyright: 0 errors
pylint: 9.93/10

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

.pylintrc

@@ -419,7 +419,8 @@ disable=raw-checker-failed,
         too-many-instance-attributes,
         duplicate-code,
         import-outside-toplevel,
-        too-few-public-methods
+        too-few-public-methods,
+        unnecessary-ellipsis
 
 # Enable the message, report, category or checker with the given id(s). You can
 # either give multiple identifier separated by comma (,) or put this option