concore watch shows import_concore.m or ConcoreJavaRuntimeCore.java as the node source #618

concore watch sometimes shows the wrong file as a node's source.

_detect_source() (watch.py line 200) only skips files starting with concore, so import_concore.m (MATLAB nodes) and ConcoreJavaRuntimeCore.java (Docker Java nodes) can get picked instead of the real source.

Repro: build demo/sampleM.graphml with controllerM.m renamed to pidM.m, then run concore watch <study> --once. Source shows import_concore.m instead of pidM.m.

Tested on dev at 8e0913e, Python 3.12.10