chore: fill in pyproject classifiers (Python 3.10-3.13, Terminals, Code Generators)

PyPI was showing `corecoder` under "Programming Language :: Python :: 3"
only, which hides it from searches that filter on specific Python
versions. Added explicit 3.10 through 3.13 entries plus topic tags that
actually match the project (Terminals, Code Generators) and
"Operating System :: OS Independent".

No code change; picks up on the next PyPI release.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: he-yufeng

pyproject.toml

@@ -18,8 +18,15 @@ classifiers = [
     "Environment :: Console",
     "Intended Audience :: Developers",
     "License :: OSI Approved :: MIT License",
+    "Operating System :: OS Independent",
     "Programming Language :: Python :: 3",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: 3.13",
     "Topic :: Software Development",
+    "Topic :: Software Development :: Code Generators",
+    "Topic :: Terminals",
 ]
 dependencies = [
     "openai>=1.0",