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>

bot_bottle/manifest_agent.py

@@ -161,7 +161,7 @@ class Agent:
         git_raw = d.get("git-gate")
         if git_raw is not None:
             gd = as_json_object(git_raw, f"agent '{name}' git-gate")
-            for k in gd.keys():
+            for k in gd:
                 if k != "user":
                     raise ManifestError(
                         f"agent '{name}' git-gate.{k} is not allowed at the "