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.

README.md

@@ -144,16 +144,14 @@ Quick start for contributors:
 ```bash
 git clone https://github.com/NousResearch/hermes-agent.git
 cd hermes-agent
-git submodule update --init mini-swe-agent   # required terminal backend
 curl -LsSf https://astral.sh/uv/install.sh | sh
 uv venv venv --python 3.11
 source venv/bin/activate
 uv pip install -e ".[all,dev]"
-uv pip install -e "./mini-swe-agent"
 python -m pytest tests/ -q
 ```
 
-> **RL Training (optional):** To work on the RL/Tinker-Atropos integration, also run:
+> **RL Training (optional):** To work on the RL/Tinker-Atropos integration:
 > ```bash
 > git submodule update --init tinker-atropos
 > uv pip install -e "./tinker-atropos"