Adv 2.0 D&D Phase 11 D1c: !zone command surface

dnd_zone_cmd.go ships handleDnDZoneCmd with subdispatch over the D1b
state machine: list, enter <id|#|name>, status, map, advance, abandon.
Bare !zone (or !zone list) shows zones available at the player's level
with !zone enter hints; an active run is flagged inline so the player
can't lose track of it.

Enter resolves zone input by ID, 1-based list index, or display name
(case/whitespace-insensitive, "the " prefix tolerated), and rejects
unknown / tier-locked zones plus duplicate concurrent runs without
clobbering the active run. Status reports current room / cleared /
loot / GM mood with a band label (effusive/friendly/neutral/grumpy/
hostile per design doc §3.2). Map prints an ASCII layout with ✓ for
cleared rooms and ▶ for the current room. Advance is a deliberate D1c
stub that calls markRoomCleared and reports the next room — combat
resolution per room wires in D1e. Abandon delegates to abandonZoneRun
and is idempotent (no-active surfaces a friendly DM, not an error).

Wired into adventure.go OnMessage right after the existing D&D
commands. 10 new tests cover dispatch (no-char nudge, list with char,
enter by ID and by index, unknown-zone rejection, duplicate-run guard,
status/map with no run, advance moves the room cursor, abandon clears
active and is idempotent), resolveZoneInput across ID/display/index/
case forms, and gmMoodLabel band edges. Full repo test suite green
(modulo a pre-existing RNG flake in
TestSimulateCombat_FirstAttackBonusImprovesEarlyHits unrelated to this
change).

TwinBee narration + mood triggers land in D1d.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

internal/plugin/adventure.go

@@ -247,6 +247,9 @@ func (p *AdventurePlugin) OnMessage(ctx MessageContext) error {
 	if p.IsCommand(ctx.Body, "level") {
 		return p.handleDnDLevelCmd(ctx)
 	}
+	if p.IsCommand(ctx.Body, "zone") {
+		return p.handleDnDZoneCmd(ctx, p.GetArgs(ctx.Body, "zone"))
+	}
 
 	// 1. Arena commands (work in rooms and DMs)
 	if p.IsCommand(ctx.Body, "bail") {