Linux terminals truncate input after 4096 chars.
testdata is Frankenstein from project Gutenberg, which are long out of copyright.
Also fix loss of coherence after long context caused by incorrect IsGlobalLayer.
Move that to config.h and use max_seq_len as the initializer to make this clear.
Also avoid dynamic allocation for GriffinActivations.
PiperOrigin-RevId: 772333225
Fix missing pos increment for last prefill and check that in gemma_test.
Thanks to @ufownl for pointing this out.
Change argument lists to QBatch with accessors.
Increase default seq_len to 8k.
PiperOrigin-RevId: 771937385