Route tleCatalogNumber() and noradIdFromSatnum() through one decoder that
accepts only plain digits or a valid Alpha-5 field. parseInt and Number()
read '2554A', '255 4', '-1234', '0x1F0', '1.5' and blank as numbers; they
now return null/NaN. Digit satnums of any length still decode, so OMM
satrecs numbered past 99999 keep working.
Add a layer test that several Alpha-5 satellites survive ingestion dedupe,
the changelog fragment for #767, and note in CURRENT-STATE that this is
Alpha-5 TLE compatibility and malformed fields are rejected.
Catalog numbers above 99999 arrive in a TLE as Alpha-5: a letter A-Z,
skipping I and O, stands for 10-33 in the ten-thousands place, so 100000
is A0000. satellite.js keeps the field as the string satrec.satnum, and
the three catalog builders converted it with Number(), which gives NaN;
the Set and Map used to deduplicate and store treat NaN as equal to NaN,
so the first such satellite was stored under NaN and every later one was
dropped as a duplicate (#751). The satellite tools read the same field
with parseInt and reported no number, so such a satellite could not be
found by it.
The decoder lives in src/sources/tle.js, beside parseTleText, which the
layer and the tools both import already: noradIdFromSatnum() for the
three builders, and tleCatalogNumber() decodes through the same function.
Every other field reads as it did before: Number() in the layer,
parseInt or null in the tools.
The satellites layer parsed catalog text inside its Cesium-backed orbit
owner. Move the parser unchanged to src/sources/tle.js, add a catalog
number helper, and have the layer delegate to it so code outside the
layer can read TLE text without loading rendering.