TSN v3.0.0-rc.19

Fixes the first thing a new user hits.

In rc.18, ./tsn --data-dir ./miner-data -t 10 started a v1 node on
tsn-testnet-v13 — a network retired in May with no peers left. It printed
"Creating new blockchain", "Node synced (height: 0)" and "MINING ACTIVE",
so it looked healthy while mining a private chain from height 0, alone.

A gen4 build now refuses that path and prints the command that works.

Running it

./tsn new-wallet                       # note the Address it prints
./tsn miner-v2 --miner-pk-hash <64-hex> -t <threads>

No --peer needed: the node discovers the mesh and bootstraps from a
published snapshot on its own. Other roles: service-node, cortex-v2,
ingress.

Everything from rc.18 is included — the mining live-lock fix, the memory work
(fleet 60 GB to 7), blocks from 229,804 to 8,707 bytes, and the self-heal
wiring guard.

sha256: 1c1ff8fe034f0476741a879f9e59d6545fb3d1418689e5284a581a4965442fd4