refactor: fix unused imports, long lines, and type issues

Remove 35+ unused imports across 20+ files (W0611). Wrap 19 lines
to fit under 100 character limit (C0301). Add type casts and
annotations in egress_addon_core.py to resolve pyright errors
caused by JSON parsing of untyped objects.

Key changes:
- Remove unused imports (abstractmethod, mock utilities, etc)
- Split long lines at logical breaks (method calls, error messages)
- Add typing.cast() for proper type inference in JSON parsing
- Explicit type annotations for dict/list accesses

Results:
- Pylint rating: 8.73/10
- egress_addon_core.py: 0 pyright errors (was 15)
- All W0611 and C0301 issues fixed

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

bot_bottle/supervise_server.py

@@ -159,7 +159,10 @@ TOOL_DEFINITIONS: list[dict[str, object]] = [
             "properties": {
                 "host": {
                     "type": "string",
-                    "description": "The hostname to allow (e.g. 'api.github.com'). Case-insensitive on match.",
+                    "description": (
+                        "The hostname to allow (e.g. 'api.github.com'). "
+                        "Case-insensitive on match."
+                    ),
                 },
                 "path_allowlist": {
                     "type": "array",