Adv 2.0 D&D Phase R R3-R5: Combat-link, zone loot, fishing, economy

R3 — Combat Event Integration:
- dnd_expedition_combat.go: Combat Interrupt rolls (§4.2) with
  threat-clock and Ranger-wilderness modifiers; Patrol Encounters
  scaled by threat level; recordZoneKill writer with monsterKillTags.
- Interrupt gate at head of handleHarvestCmd; patrol gate before
  resolveRoom in zoneCmdAdvance; kill writer wired into combat-win
  paths.

R4a — Zone Loot Tables:
- dnd_zone_loot.go: §5 loot drop tables for all 10 zones × 5 tiers
  with §8.1 sell-value bands. dropTierFromCR brackets + boss floor.
- Hooks on combat-win in resolveCombatRoom, resolveBossRoom,
  runHarvestInterrupt, tryPatrolEncounter.

R4b — Fishing Integration:
- dnd_zone_fish.go: fishingZones allow-list, fishingSkillBonus,
  rangerRareCatchUpgrade (§6.2), feywildFishDistortion narration.
- §6.1 fish entries added to resource registry for Forest, Sunken
  Temple, Underdark, Feywild zones.
- !fish wired through handleHarvestCmd; zoneItemFlavor matrix
  populated for all 10 zones × all loot items.

R5 — Economy Integration:
- dnd_economy.go: !sell (post-expedition gate, single CHA Persuasion
  DC 17 → +15% bump), !craft (§8.2 4 exemplar recipes), !lore
  (INT/Arcana DC 15 recipe discovery).
- dnd_known_recipe table for persistent recipe discovery.

Flavor reuse: HarvestInterrupt, PatrolEncounter, CombatVictory,
PlayerDeath, LootDrop*, FeywildTimeDistortion* — all existing pools.
No new flavor file.

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

internal/plugin/dnd_expedition_harvest.go

@@ -350,6 +350,9 @@ func (p *AdventurePlugin) handleHarvestCmd(ctx MessageContext, action HarvestAct
 	if err != nil || char == nil {
 		return p.SendDM(ctx.Sender, "No D&D character found. Run `!setup` first.")
 	}
+	if action == HarvestFish && !isFishingZone(exp.ZoneID) {
+		return p.SendDM(ctx.Sender, "There's no water to fish in here. `!fish` works only in Forest of Shadows, Sunken Temple, Underdark, or Feywild Crossing.")
+	}
 	if exp.RunID == "" {
 		return p.SendDM(ctx.Sender, "No active region run. Try `!region` to refresh, or restart the expedition.")
 	}
@@ -372,12 +375,56 @@ func (p *AdventurePlugin) handleHarvestCmd(ctx MessageContext, action HarvestAct
 	}
 
 	res, _ := FindZoneResource(exp.ZoneID, nodes[idx].ResourceID)
+
+	// §4.2 Combat Interrupt roll — gates the harvest attempt.
+	zone, _ := getZone(exp.ZoneID)
+	interrupt, intTotal := resolveCombatInterrupt(
+		exp.ThreatLevel, int(zone.Tier), char.Class, exp.ZoneID, nil)
+	var interruptHeader string
+	switch interrupt {
+	case InterruptNoise:
+		_ = applyThreatDelta(exp.ID, 2, "harvest noise (§4.2)")
+		interruptHeader = fmt.Sprintf(
+			"_⚠ Noise drifts through the corridors (interrupt roll %d). Threat +2._\n\n",
+			intTotal)
+	case InterruptStandard, InterruptElite, InterruptPatrol:
+		var pre strings.Builder
+		pre.WriteString(fmt.Sprintf(
+			"**%s · %s** — interrupted before the roll (interrupt %d).\n\n",
+			strings.ToTitle(string(action)[:1])+string(action)[1:], res.Name, intTotal))
+		body, ended := p.runHarvestInterrupt(ctx.Sender, exp, run, zone, interrupt)
+		pre.WriteString(body)
+		if interrupt == InterruptElite && !ended {
+			pre.WriteString("\n\n_The node is still here — you dropped the harvest mid-strike._")
+		}
+		if interrupt == InterruptPatrol && !ended {
+			pre.WriteString("\n\n_The harvest is forfeit._")
+		}
+		// Persist node state untouched (no charge spent).
+		_ = saveHarvestNodes(exp, roomIdx, nodes)
+		_ = appendExpeditionLog(exp.ID, exp.CurrentDay, "interrupt",
+			fmt.Sprintf("%s %s kind=%d total=%d", string(action), res.ID, int(interrupt), intTotal), "")
+		return p.SendDM(ctx.Sender, pre.String())
+	}
+
 	roll := rand.IntN(20) + 1
 	mod := harvestActionAbility(char, action) + classHarvestBonus(char.Class, action)
+	if action == HarvestFish {
+		if adv, _ := loadAdvCharacter(ctx.Sender); adv != nil {
+			mod += fishingSkillBonus(adv.FishingSkill)
+		}
+	}
 	total := roll + mod
 	outcome := resolveHarvestOutcome(total, res.DC)
+	outcome = rangerRareCatchUpgrade(char.Class, action, outcome, nil)
 
 	var b strings.Builder
+	if interruptHeader != "" {
+		b.WriteString(interruptHeader)
+	}
+	if dist := feywildFishDistortion(exp.ZoneID, action, nil); dist != "" {
+		b.WriteString(dist)
+	}
 	verb := strings.ToTitle(string(action)[:1]) + string(action)[1:]
 	b.WriteString(fmt.Sprintf("**%s · %s** — d20=%d + %d = **%d** vs DC %d\n\n",
 		verb, res.Name, roll, mod, total, res.DC))