Fix renderer typing, preserve message text, and harden crypto key handling

Fix abstract renderer signatures and add small stubs so type checkers can
see expected attributes (e.g. username, _decrypt). This removes several
mypy false-positives that were caused by mixin/ABC mismatches.
Preserve message text containing ':' by using split(':', 1) in both
DefaultClientRenderer and RichClientRenderer.
Normalize renderer APIs: print_chat(...) now takes the response mapping
and returns None (matches runtime behavior).
Make RSA symmetric-key request more robust: read r.content instead of a
fixed-size r.raw.read(999), avoiding truncated key material.
Improve _connect_ws exception handling in client to ensure a valid
Exception is re-raised if connection attempts fail.
Correct server/service typing: memory_msgs is now typed as
list[Message] and we null-check incoming payload text before creating a
new Message.
Replace manual package list in setup.py with setuptools.find_packages()
so packaging uses valid Python package names.
Installed types-requests in the project venv so mypy no longer flags the
requests import.
Verification: ran python -m compileall and mypy cmd_chat — no issues
remain.
Notes:

Wire format still uses Python literal evaluation in some places (existing
behavior); switching to JSON for client/server payloads is recommended as a
follow-up for robustness and security.

cmd_chat/client/core/abs/abs_crypto.py

@@ -19,7 +19,7 @@ class CryptoService(ABC):
         raise NotImplementedError("Need to implement generate keys method")
 
     @abstractmethod
-    def _get_generated_keys(self) -> list[str]:
+    def _get_generated_keys(self) -> tuple:
         raise NotImplementedError("Need to implement get generated keys method")
 
     @abstractmethod

cmd_chat/client/core/abs/abs_renderer.py

@@ -2,23 +2,33 @@ from abc import ABC, abstractmethod
 
 
 class ClientRenderer(ABC):
+    # These attributes are expected to be provided by subclasses
+    # (typically via multiple inheritance with CryptoService)
+    username: str
+    
+    @abstractmethod
+    def _decrypt(self, message: str) -> str:
+        """Decrypt an encrypted message (provided by crypto mixin)."""
+        raise NotImplementedError("Need to implement _decrypt")
 
     @abstractmethod
     def print_message(self, message: str) -> str:
         raise NotImplementedError("Need to implement print_message")
 
     @abstractmethod
-    def clear_console(self, message: str) -> str:
+    def clear_console(self) -> None:
+        """Clear the client console (platform-specific)."""
         raise NotImplementedError("Need to implement clear_console")
 
     @abstractmethod
-    def print_ip(self, url: str, username: str):
+    def print_ip(self, ip: str) -> str:
         raise NotImplementedError("Need to implement print_ip")
 
     @abstractmethod
-    def print_username(self):
+    def print_username(self, username: str) -> str:
         raise NotImplementedError("Need to implement print_username")
 
     @abstractmethod
-    def print_chat(self) -> list[str]:
+    def print_chat(self, response) -> None:
+        """Render chat payload (response is expected to be a mapping with 'messages' and 'users_in_chat')."""
         raise NotImplementedError("Need to implement print_chat")