Check the keys of the PALS root node

[DavidSagan]

The problem

A misspelled key in the PALS root node was silent. From a real file:

PALS:
  extension_names:      # should be extension_labels
    names:
      Bmad

Nothing is registered, so the first sign of the mistake was a complaint about the data the extension was meant to cover, an element away:

element 'beginning_b1': unknown parameter 'Bmad'

Now:

PALS node: unknown key 'extension_names'; did you mean 'extension_labels'?

The fix

• known_pals_keys — the root's closed vocabulary: the six of fundamentals.md s:palsroot, plus phase_space_coordinates (coordinates.md) and the two ways a file names another, include and load.

• check_pals_root — checks the PALS node's own keys, called from check_pals_names alongside the existing walk. A key registered as an extension label is skipped as it is everywhere else. Only this node's keys are checked: anything outside PALS is outside the standard and ignored (fundamentals.md).

• suggest gained an optional edit cap, default 2, so every existing caller is unchanged. extension_names is four edits from extension_labels, past the usual cap; the root vocabulary is nine names with nothing in common, so a looser cap there cannot match at random.

Tests

Three new cases in test_check.cpp (suite: 224 cases, all passing):

• the misspelled root key is reported, with the suggestion;
• every documented root key passes clean, and a registered name still covers the element data it was registered for;
• a root key matching a registered prefix is left alone.

The first is verified as a real regression by stubbing out the call: that case fails, the rest pass. Every file in lattice_files/ was run through the checker as well -- no new reports, so the vocabulary is not missing anything the examples use.

🤖 Generated with Claude Code