hook: session-start.sh

Part 3 · EACH TOOL · Slide 45 of 60

Event: SessionStart · timeout 30 s · exit 0 always.
Prints the banner (version, runtime), the discipline anchor,
the offload rule, the ledger law, the pulse — then the BRIEF
PACKET: the estate's state, git position, newest ship, gate and
correction, last eight ledger lines. Silences the "go read
START-HERE" nudge when the packet already carries the trail.