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/egress_addon.py

@@ -38,7 +38,12 @@ from mitmproxy import http  # type: ignore[import-not-found]
 # Absolute import (NOT `from .egress_addon_core`) — the
 # container drops both files flat into /app/ so they are sibling
 # top-level modules to mitmdump's loader, not a package.
-from egress_addon_core import Route, decide, is_git_push_request, load_routes  # type: ignore[import-not-found]
+from egress_addon_core import (  # type: ignore[import-not-found]
+    Route,
+    decide,
+    is_git_push_request,
+    load_routes,
+)
 
 
 DEFAULT_ROUTES_PATH = "/etc/egress/routes.yaml"