build: add packaging and pin the verified Telethon version

Telethon 2.0 is alpha with a renamed API surface, hence the <2 bound.
requirements.txt records 1.44.0, the version the API probes were run
against, so a later resolver bump cannot silently change the semantics
the traversal depends on.

pyproject.toml

@@ -0,0 +1,25 @@
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
+[project]
+name = "telegram-exporter"
+version = "0.1.0"
+description = "Export all media from a Telegram group to local disk, grouped by post, resumably."
+requires-python = ">=3.12"
+license = { file = "LICENSE" }
+# Telethon 2.0 is alpha with a renamed API surface. requirements.txt pins the
+# exact version the API probes were verified against.
+dependencies = ["telethon>=1.41,<2"]
+
+[project.optional-dependencies]
+dev = ["pytest>=8"]
+
+[project.scripts]
+tg-export = "telegram_exporter.cli:main"
+
+[tool.hatch.build.targets.wheel]
+packages = ["src/telegram_exporter"]
+
+[tool.pytest.ini_options]
+testpaths = ["tests"]

requirements.txt

@@ -0,0 +1,6 @@
+# Pinned to the Telethon version the API probes were verified against.
+# Regenerate with `pip freeze` only after re-running spike/probe_telethon_api.py.
+pyaes==1.6.1
+pyasn1==0.6.4
+rsa==4.9.1
+Telethon==1.44.0