refactor(acp): rewrite imports and update infra for hermes_agent.acp

Rewrite all acp_adapter imports to hermes_agent.acp in source, tests,
and pyproject.toml. Convert relative imports to absolute per manifest
convention. Strip sys.path hack from entry.py (redundant with editable
install). Update pyproject.toml entry point and packages.find.

Part of #14586, #14182

hermes_cli/main.py

@@ -8516,7 +8516,7 @@ Examples:
     def cmd_acp(args):
         """Launch Hermes Agent as an ACP server."""
         try:
-            from acp_adapter.entry import main as acp_main
+            from hermes_agent.acp.entry import main as acp_main
 
             acp_main()
         except ImportError: