fix(cli): use canonical environment names in hud init

[solvemproblr]

Issue

hud init my-env generated Environment(name="my_env") while the package and deployed registry used my-env. The mismatch caused tasks to reference a registry name that did not exist.

Solution

Use the SDK's canonical environment-name normalization when generating env.py, so both names remain my-env.

Tests

• uv run --extra dev pytest -q hud/cli/tests/test_init.py
• Ruff format and lint
• ty check hud/cli/init.py

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Note

Low Risk
Only affects newly generated local scaffolds from hud init; no auth, sync, or runtime behavior changes in this diff.

Overview
hud init no longer derives environment names with a local underscore slugifier. Local blank scaffolds now call shared normalize_environment_name on the target directory name, so generated env.py uses the same hyphenated, registry-style spelling (e.g. my-cool-env instead of my_cool_env).

The inline _python_name helper was removed in favor of that shared utility. test_init expectations were updated to match the hyphenated Environment(name=...) in the scaffold output.

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