Wheel packaging of `migrations/` and `static/` has no test guard — a regression would ship silently

[vishalkalbi27]

Summary

The recent fix that packages migrations/ and static/ into the wheel (branch
fix/package-static-assets-in-wheel) is correct, but nothing in the test suite guards it.
If the packaging config is reverted or drifts, every test still passes and a broken wheel ships —
which is exactly how the original bug went unnoticed.

Background — the bug that was fixed

Two failures existed only in a real (non-editable) wheel install, never in a checkout or the
Docker deploy (which uses pip install -e):

1. Migrations — store.MIGRATIONS_DIR resolved via Path(__file__).parents[3] / "migrations" / "core".
   In a checkout that is <repo>/migrations/core ✅. In a wheel, store.py lands in site-packages/,
   so parents[3] points at the venv root → the directory doesn't exist → glob() returns [] →
   the server boots on an empty schema with no error at all.
2. Static assets — mcp_http._STATIC_DIR = Path(__file__).parent / "static", but static/ was never
   listed in pyproject.toml, so it wasn't in the wheel → StaticFiles(directory=…) raises
   "Directory does not exist" when building the app.

Why the test suite cannot catch this

Tests install the package editable (dev.py: --with-editable packages/agami-core[model,server]),
so the data dirs resolve into the source tree, which exists regardless of what pyproject.toml
packages: