refactor: remove mini-swe-agent dependency — inline Docker/Modal backends (#2804)

Drop the mini-swe-agent git submodule. All terminal backends now use
hermes-agent's own environment implementations directly.

Docker backend:
- Inline the `docker run -d` container startup (was 15 lines in
  minisweagent's DockerEnvironment). Our wrapper already handled
  execute(), cleanup(), security hardening, volumes, and resource limits.

Modal backend:
- Import swe-rex's ModalDeployment directly instead of going through
  minisweagent's 90-line passthrough wrapper.
- Bake the _AsyncWorker pattern (from environments/patches.py) directly
  into ModalEnvironment for Atropos compatibility without monkey-patching.

Cleanup:
- Remove minisweagent_path.py (submodule path resolution helper)
- Remove submodule init/install from install.sh and setup-hermes.sh
- Remove mini-swe-agent from .gitmodules
- environments/patches.py is now a no-op (kept for backward compat)
- terminal_tool.py no longer does sys.path hacking for minisweagent
- mini_swe_runner.py guards imports (optional, for RL training only)
- Update all affected tests to mock the new direct subprocess calls
- Update README.md, CONTRIBUTING.md

No functionality change — all Docker, Modal, local, SSH, Singularity,
and Daytona backends behave identically. 6093 tests pass.

tests/tools/test_terminal_requirements.py

@@ -18,9 +18,8 @@ def _clear_terminal_env(monkeypatch):
         monkeypatch.delenv(key, raising=False)
 
 
-def test_local_terminal_requirements_do_not_depend_on_minisweagent(monkeypatch, caplog):
-    """Local backend uses Hermes' own LocalEnvironment wrapper and should not
-    be marked unavailable just because `minisweagent` isn't importable."""
+def test_local_terminal_requirements(monkeypatch, caplog):
+    """Local backend uses Hermes' own LocalEnvironment wrapper."""
     _clear_terminal_env(monkeypatch)
     monkeypatch.setenv("TERMINAL_ENV", "local")
 
@@ -64,7 +63,7 @@ def test_modal_backend_without_token_or_config_logs_specific_error(monkeypatch,
     monkeypatch.setenv("TERMINAL_ENV", "modal")
     monkeypatch.setenv("HOME", str(tmp_path))
     monkeypatch.setenv("USERPROFILE", str(tmp_path))
-    monkeypatch.setattr(terminal_tool_module, "ensure_minisweagent_on_path", lambda *_args, **_kwargs: None)
+    # Pretend swerex is installed
     monkeypatch.setattr(terminal_tool_module.importlib.util, "find_spec", lambda _name: object())
 
     with caplog.at_level(logging.ERROR):