The first draft of these notes estimated the doubled pool at 103.5 GiB
held / ~5 GiB host remainder. Both numbers were wrong — they costed the
KV alone and ignored that the arena shrinks when MAX_TOK drops. Measured:
pool 262144 / max_tok 32768 -> 96.3 GiB held, 12.1 GiB host left
pool 524288 / max_tok 16384 -> 94.6 GiB held, 13.8 GiB host left
The doubled pool is 1.7 GiB cheaper overall. Also records the failed
first attempt verbatim, since the silent-revert failure mode is the thing
a future operator most needs to recognise, and adds the HALOGEN_MAX_TOK
row to the deployed-flags table (the "baked 32768" line it overrode was
stale).