feat: add warnings mode for import/export handlers, commands

can now specify `--warn` for import/export CLI, to get diff email when
changes occur.

this also adds `get_import_handler()` and friends, via app provider.

also declare email settings for the 2 existing importers

pyproject.toml

@@ -26,6 +26,7 @@ classifiers = [
 ]
 requires-python = ">= 3.8"
 dependencies = [
+        "humanize",
         "makefun",
         "SQLAlchemy-Utils",
         "WuttJamaican[db]>=0.16.2",
@@ -37,6 +38,13 @@ docs = ["Sphinx", "enum-tools[sphinx]", "furo", "sphinxcontrib-programoutput"]
 tests = ["pylint", "pytest", "pytest-cov", "tox", "Wutta-Continuum"]
 
 
+[project.entry-points."wutta.app.providers"]
+wuttasync = "wuttasync.app:WuttaSyncAppProvider"
+
+[project.entry-points."wuttasync.importing"]
+"import.to_versions.from_wutta" = "wuttasync.importing.versions:FromWuttaToVersions"
+"import.to_wutta.from_csv" = "wuttasync.importing.csv:FromCsvToWutta"
+
 [project.entry-points."wutta.typer_imports"]
 wuttasync = "wuttasync.cli"