fix: missing minisweagent_path module + add nix checks

- Patch upstream pyproject.toml to include minisweagent_path in py-modules
- Copy mini-swe-agent/src/minisweagent into package for importability
- Add 3 nix checks: package-contents, cli-commands, doctor
- All binaries tested: hermes, hermes-agent, hermes-acp
- hermes gateway, config, status, claw migrate all verified working

flake.nix

@@ -17,6 +17,11 @@
           default = self.packages.${system}.hermes-agent;
         };
 
+        checks = import ./checks.nix {
+          inherit pkgs;
+          hermes-agent = self.packages.${system}.hermes-agent;
+        };
+
         devShells.default = pkgs.mkShell {
           packages = [ self.packages.${system}.hermes-agent ];
         };