fix: Inconsistent llamafactory dependency version across README, pyproject.toml, and CI

[luojiyin1987]

Problem

The llamafactory dependency version is inconsistent across three places:

Location	Current State	Issue
README.md (line 93)	pip install llamafactory==0.9.3	Fixed to 0.9.3
pyproject.toml (line 29)	dynamic = ["dependencies"]	Not declared as formal dependency
.github/workflows/test.yml (line 57)	uv pip install llamafactory	Installs latest, no version pin

Why This Matters

1. Users follow README → install 0.9.3
2. CI installs latest → tests may pass but code breaks for users
3. pyproject.toml doesn't declare it → pip install -e . doesn't install it
4. llamafactory API changes → breakage happens silently

Solution

1. Add to pyproject.toml as a formal dependency with version range
2. Pin CI to the same version as README
3. Document the supported llamafactory version range

Suggested Change

# pyproject.toml
dependencies = [
    "llamafactory>=0.9.3,<0.10.0",  # pin to minor version
]

# .github/workflows/test.yml
- uv pip install llamafactory==0.9.3  # match README

Or consider using a requirements.txt for exact version pinning.