Expedition autopilot Phase 4 + rogue sneak attack + TwinBee voice sweep

Tedium-removal pass driven by live play feedback. Three big threads:

Expedition autopilot Phase 4 — background auto-run + harvest-until-dry:
- New expeditionAutoRunTicker walks active expeditions every 15min
  (5min tick, per-expedition CAS on new last_autorun_at column). Skips
  combat sessions, briefing/recap quiet windows, expeditions <30min old.
- Walks up to 3 rooms/tick with compact narration; suppresses DMs when
  0 rooms walked or just hitting the per-tick cap (no "stretch complete"
  filler). Player only hears from the bot when a real decision is needed.
- Compact mode: one-line combat narration for trash/elite, auto-resolves
  elite doorways via the forward-sim engine (boss still pauses). Threaded
  via new advanceOnceWithOpts → resolveRoom → resolveCombatRoom.
- Auto-harvest now grinds each Common/Uncommon node until dry (cap at 8
  attempts/visit), mirroring manual !scavenge retries. Rare+ still pauses.
- Ambient ticker: anti-repeat by Kind via new last_ambient_kind column
  (avoids two pack_rat DMs in a row when the pool only has 6 lines).
- !expedition go <n> now routes to the fork-choice handler when active +
  numeric; fork footer rewritten to suggest !expedition go instead of
  !zone go. Boss/Elite doorway: formatNextRoomMessage routes the action
  hint by next room type and autopilot loop breaks via new nextRoomType
  field so "Room X/Y — Boss" doesn't double-print with contradictory
  hints (!zone advance vs !fight).
- runAutopilotWalk extracted from expeditionCmdRun so foreground and
  background share the loop body.

Rogue Sneak Attack actually exists now:
- Audit found the rogue's "Sneak Attack" passive was AutoCritFirst +
  5% damage rider. No Nd6, ever. Phase 2 Monte Carlo masked this
  with a small flat buff; the class's defining mechanic never matched
  its tooltip or 5e identity.
- Added SneakAttackDie int to CombatModifiers, per-hit Nd6 in
  combat_primitives.go (same lane as DivineStrikePerHit). Scales with
  level: 1d6 at L1-2 ... 4d6 at L7-8 ... capped at 10d6 at L19-20.
- AutoCritFirst + 5% rider retained as bonuses on top of working sneak
  attack — preserves the opener-burst feel.
- L7 rogue expected per-hit ~8 → ~22 damage. Valdris fight math goes
  from "16 rounds to kill, die in 8" to winnable.

TwinBee voice sweep (Phase B3):
- ~530 line changes across 24 files replacing third-person "TwinBee
  notes/files/tracks/respects/..." constructions with first-person
  inside flavor string literals. Code identifiers (TwinBeeLine,
  twinBeeLine, etc.), chat-prefix labels (🎭 **TwinBee:**), item names
  (TwinBee's Bell), achievements, and game-title references in
  fun.go (Konami TwinBee ship) left intact.
- Catches a real bug: Valdris fight rendered "TwinBee marks the
  Legendary Resistance" mid-combat in third person, contradicting
  the Phase B2 convention.

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

internal/db/db.go

@@ -323,6 +323,16 @@ func runMigrations(d *sql.DB) error {
 		// Real-time between-day events fire at most once per ambientCooldown
 		// while an expedition is active; idempotent CAS on this column.
 		`ALTER TABLE dnd_expedition ADD COLUMN last_ambient_at DATETIME`,
+		// Kind-level anti-repeat for the ambient ticker: the previous
+		// pick's Kind biases the next pick away from itself so two
+		// back-to-back pack_rat / monologue / etc. DMs don't read as
+		// duplicates on small flavor pools.
+		`ALTER TABLE dnd_expedition ADD COLUMN last_ambient_kind TEXT NOT NULL DEFAULT ''`,
+		// Expedition autopilot Phase 4 — background auto-run ticker. Real-
+		// time room-walking between player commands so the player only
+		// engages when a fork / elite / boss / supply pinch actually
+		// needs a decision. CAS-claim on this column gates re-entry.
+		`ALTER TABLE dnd_expedition ADD COLUMN last_autorun_at DATETIME`,
 	}
 	for _, stmt := range columnMigrations {
 		if _, err := d.Exec(stmt); err != nil {
@@ -1890,6 +1900,8 @@ CREATE TABLE IF NOT EXISTS dnd_expedition (
     last_briefing_at DATETIME,
     last_recap_at    DATETIME,
     last_ambient_at  DATETIME,
+    last_ambient_kind TEXT NOT NULL DEFAULT '',
+    last_autorun_at  DATETIME,
     last_activity    DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
     completed_at     DATETIME
 );