"""`atlas planet` — the third rung of the spatial ladder (D-243).

Nested under `atlas` rather than standing alone because atlas coordinates
world-location generation: the ladder is one subject, and `planet` is a rung of
it, not a peer. Same reason `atlas map` holds the star-map verbs.

Formerly `tooling/planet-gen/`, 30 files reachable only by path. The move fixed
what a hyphenated directory made impossible — these modules import each other,
and until now did it by mutating `sys.path` at import time.

**Every repo-root computation here was wrong on arrival.** The originals
computed `Path(__file__).parent / ".." / ".."`, correct while the files sat two
levels deep and silently wrong at four. That is the fifth-through-ninth
instance of this trap in the port, and it fails quietly: a gate resolves its
inputs to a directory that does not exist, finds nothing to check, and exits 0.
They now call `config.repo_root()`, which asks git.

`PLANET_DIR` (was `TOOLING_DIR`) still means "beside this code" and still
resolves correctly — the data files it addresses, `biomes.toml`,
`sol_overrides.json`, `sol_markers/` and `earth_blocklist.txt`, moved with it.
The rename is so the name stops claiming to be `tooling/`.
"""