adventure: bored adventurers go into dungeons on their own

A player who stops tending their adventurer doesn't stop having one. After
24h with no action against Adventure, the character gets restless and leaves
on an expedition by itself: the easiest zone its level band allows, the
cheapest supplies it can afford, and whatever gear was already on the rack.

Everything downstream of the start was already autonomous — the autopilot
walks rooms, drives elite and boss fights on the turn engine, camps, harvests
and picks forks. The only thing that ever needed a human was `!expedition
start`, so that's all this adds: a 30m ticker plus a clock.

It never buys or equips anything, and that is the whole mechanic: a neglected
adventurer grinds half-starved runs on rusting gear and comes home taxed. The
prodexercise killed an L4 mage four rooms in on its first run.

The clock is a new column. Every existing timestamp is unusable: last_active_at
is auto-bumped by saveAdvCharacter (the autopilot would refresh a bored
character's own idle clock), loadAdvDailyActivity counts the autopilot's own
expedition logs, and user_stats.updated_at is chat presence, not a game action.
last_player_action_at is written only by markPlayerAction, from a real player
action against Adventure — any interface, not just Matrix.

Raid zones (raidContentWarning: the party-tuned T5 bosses with a 0% solo clear)
are avoided while anything else is in band. At L13+ they're all that's left, and
the adventurer goes in anyway and loses. That's intended.

dnd_expedition.boredom + isBoredomDriven stop a run nobody asked for from
shielding an absent player from the idle reaper or holding their streak. A
manually-started expedition still holds it while the autopilot walks it.

Robbie visits and pays silently for idle players — he was going to file a daily
public bulletin about people who stopped playing weeks ago.

Note for anyone touching the time-scanning queries here: modernc.org/sqlite
rebuilds a time.Time from the column's declared type, and COALESCE()/MAX() erase
it. playerIsIdle fails open, so a broken scan there declares the whole server
idle. Both it and lastExpeditionByZone select declared columns and fold in Go,
and the tests seed real rows so the scan actually executes.

internal/flavor/twinbee_expedition_flavor.go

@@ -25,6 +25,25 @@ var ExpeditionStart = []string{
 	"Like the opening screen of a long RPG — the kind that asks for your name and warns you to find a comfortable position because this is going to take a while. I've found a comfortable position. I suggest you do the same.",
 }
 
+// ─────────────────────────────────────────────────────────────────────────────
+// EXPEDITION START — BOREDOM (the adventurer left without you)
+//
+// Fired by the boredom ticker after a long silence. The player is not
+// reading this live; it's a note left on the table. Deadpan, faintly
+// reproachful, never cruel — and never pretending the gear got checked,
+// because it didn't (gogobee_boredom_plan.md §5).
+// ─────────────────────────────────────────────────────────────────────────────
+
+var ExpeditionBoredomStart = []string{
+	"You didn't come. That's alright — it happens, and I'm not going to make it a thing. But the sword was getting heavy on the wall and I've packed what we had. Which was not much. Noted for the record, not as a complaint.",
+	"I waited. Then I waited past the point where waiting was the sensible option, and somewhere in there the waiting turned into leaving. We're going. Same kit as last time, because last time is when you last touched it.",
+	"Here's the situation: there's a dungeon, there's daylight, and there's nobody telling me not to. I've made a decision. I hope it was the one you'd have made, though I concede I have no way of checking.",
+	"Supplies: the cheapest available. Equipment: whatever was already on the rack. Plan: walk in, see what happens. I'm aware of how that sounds. I'm going anyway.",
+	"The gear hasn't moved since you left it. I checked. I checked twice, actually, in case the first check was wrong, and it wasn't. So we go as we are — which is to say, as we were.",
+	"Restlessness is not a stat I can show you on the sheet, but it accumulates, and it has. Off we go. Lightly provisioned and unimproved, but off.",
+	"I've done the arithmetic on standing still and it doesn't come out well. So: a dungeon, one supply pack, and the same armour that's been good enough up to now. 'Good enough' is doing a lot of work in that sentence.",
+}
+
 // ─────────────────────────────────────────────────────────────────────────────
 // MORNING BRIEFINGS — Generic
 // ─────────────────────────────────────────────────────────────────────────────