fix(docker): allow README.md in build context for hatchling metadata

[Elshayib]

Summary

Fixes Docker publish CI failure (issue #198) where excluded and but tried to copy them.

Root Cause

• line 31 () excluded
• line 32 () excluded
• line 14 did in the builder stage
• Buildx build context filter removed these files → "not found" error during

The field in requires the file to exist at build time for hatchling to read the long description.

Changes

1. ****: Added allowlist entries and so they're included in the build context
2. ****: Copy in the builder stage (only and needed; is inline in pyproject.toml)

Testing

• ✅ Docker build succeeds locally
• ✅ Image runs correctly ( works)
• ✅ All 639 tests pass
• ✅ No regressions in lint/mypy/bandit

Notes

• and are only needed at build time for hatchling metadata
• They are NOT copied to the final runtime image (multi-stage build discards builder stage)
• This keeps the final image minimal as intended