zones: make locked doors openable and stop autopilot stalling on them

Locks were fully implemented as pass/fail gates and nothing else. A
Perception or stat check rolls once per (run, edge), seeded so it can't
be reload-scummed — that half shipped in G5, the counterweight never did.
A bad roll simply deleted a branch of the graph for the rest of the run,
worst for a solo low-WIS character who quietly loses routes they never
learn existed. Three changes, one theme: a die roll should not be able to
permanently wall a player.

Party's best stat answers the check. evaluateEdgeLock read only the
acting character's mods, which made a party's rogue and its hired scout
decorative at every lock. Fold the whole roster — Pete included, since
excluding him would make hiring a scout worth less than the coins it
costs — and credit whoever got it open in the fork menu.

Thieves' tools as the escape hatch. A utility item (not a ConsumableDef,
or the fight engine would spend them for you) sold on Luigi's supplies
shelf, consumed by `!zone unlock <n>`. Deliberately not a skeleton key:
tools answer the two dice-driven locks only. A key lock is a quest token,
a level-min lock is progression, a region-clear lock is structure — none
of those are "you rolled badly", so none of them are pickable.

Autopilot picks a route instead of parking. The fork timeout was 8h,
which reads as "the player gets first say" and behaves as "the expedition
stops for a third of a day, at every fork" — a multi-day expedition
crosses a lot of forks. 30m keeps a genuine first say for anyone at the
keyboard. It now ranks by unvisited-then-edge-weight rather than taking
whatever the graph author happened to list first, spends tools when every
route is locked, and backtracks a room when it can't do even that, rather
than idling into the 24h reaper and losing the player days of progress to
a roll they never saw.

Sim A/B, same seeds, 90 runs/arm: 43.3% -> 42.2% clear, a single run
flipping and well inside the documented noise floor. A party+companion+pet
arm runs 31/32 clean through the new roster-folding path.

internal/plugin/dnd_zone_cmd_graph.go

@@ -188,6 +188,17 @@ func (p *AdventurePlugin) zoneCmdGo(ctx MessageContext, rest string) error {
 	if cerr != nil {
 		return p.SendDM(ctx.Sender, cerr.Error())
 	}
+	return p.commitForkChoice(ctx, run, chosen, "")
+}
+
+// commitForkChoice advances the run onto an already-validated fork option and
+// emits the arrival teaser. Split out of zoneCmdGo so `!zone unlock` — which
+// reaches the same place by paying for it — cannot drift from the plain
+// `!zone go` arrival: same region-transition hook, same camp strike, same
+// boss/elite prompt. header, if set, is printed above the move.
+func (p *AdventurePlugin) commitForkChoice(
+	ctx MessageContext, run *DungeonRun, chosen pendingChoice, header string,
+) error {
 	nextIdx, aerr := advanceZoneRunNode(run.RunID, chosen.To)
 	if aerr != nil {
 		return p.SendDM(ctx.Sender, "Couldn't advance: "+aerr.Error())
@@ -200,6 +211,7 @@ func (p *AdventurePlugin) zoneCmdGo(ctx MessageContext, rest string) error {
 	fireGraphRegionTransition(run.UserID, fromNode, nextNode)
 	nextRoom := nodeKindToRoomType(nextNode.Kind)
 	var b strings.Builder
+	b.WriteString(header)
 	if kind := autoBreakCampOnMove(ctx.Sender); kind != "" {
 		b.WriteString(fmt.Sprintf("⛺ Camp struck (**%s**) — the party moved on.\n\n", kind))
 	}