Add Cloud Agent development environment setup

[allwefantasy]

Summary

Sets up a reproducible Cloud Agent development environment for auto-coder and makes the package importable/runnable out of the box.

What's added

• .cursor/environment.json — declares the environment and runs bash .cursor/install.sh as the install step.
• .cursor/install.sh — an idempotent install script that:
  • installs the system libraries some Python deps need (libcairo2, poppler-utils, ffmpeg, python3.12-venv);
  • creates an isolated virtualenv at $HOME/autocoder-venv (avoids conflicts with Debian-managed system Python packages such as PyJWT);
  • installs requirements.txt + the package in editable mode, plus pytest for the repo's test scripts;
  • symlinks the console scripts (auto-coder, auto-coder.chat, auto-coder.run, auto-coder.serve, …) into /usr/local/bin so they're on PATH with no shell-profile mutation.

Dependency fixes (required for the package to import at all)

• Pin setuptools<81: newer setuptools removed the pkg_resources API that autocoder.common.buildin_tokenizer still imports.
• Add missing runtime deps that the code imports but requirements.txt didn't list: pandas (via pyjava), sqlmodel (autocoder.db.store), psutil (autocoder.common.run_cmd).

.gitignore

• Keep ignoring .cursor/ contents but track the two environment files.

Validation (local VM)

Check	Result
Clean install from scratch	Succeeds (auto-coder install complete: 1.0.0)
Install idempotence	Passes on re-run
auto-coder / auto-coder.chat / auto-coder.run / auto-coder.serve load	All OK
auto-coder.serve HTTP server	Starts; /docs and /openapi.json → 200; /list_files → {"files":[]}, /conf/list → {"config":{}}
Built-in tokenizer (BuildinTokenizer)	Returns real token counts
Unit tests (file_checkpoint/test_utils.py)	9 passed

Notes

• RAG mode (auto-coder.rag) with the byzer-storage backend requires ray, which upstream intentionally commented out in requirements.txt and which is incompatible with current byzerllm on the latest release. It's left as an optional extra; the core CLI, chat/run agent, and server modes all work.