🐛 skip unreachable job targets in pickJob (Issue #22)

Trees/rocks fully enclosed by impassable tiles have no passable neighbour
for A* to jump from — pathfinding always returns null, causing a tight
1.5 s retry loop that fills the work log with identical entries.

- Add hasAdjacentPassable() helper: checks all 8 neighbours of a tile
- pickJob now skips chop/mine candidates with no passable neighbour
- idleScanTimer on pathfind failure raised 1500 → 4000 ms as safety net

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/systems/VillagerSystem.ts

@@ -351,12 +351,17 @@ export class VillagerSystem {
     if (p.chop > 0) {
       for (const res of Object.values(state.world.resources)) {
         if (res.kind !== 'tree' || this.claimed.has(res.id)) continue
+        // Skip trees with no reachable neighbour — A* cannot enter an impassable goal
+        // tile unless at least one passable neighbour exists to jump from.
+        if (!this.hasAdjacentPassable(res.tileX, res.tileY)) continue
         candidates.push({ type: 'chop', targetId: res.id, tileX: res.tileX, tileY: res.tileY, dist: dist(res.tileX, res.tileY), pri: p.chop })
       }
     }
     if (p.mine > 0) {
       for (const res of Object.values(state.world.resources)) {
         if (res.kind !== 'rock' || this.claimed.has(res.id)) continue
+        // Same reachability guard for rock tiles.
+        if (!this.hasAdjacentPassable(res.tileX, res.tileY)) continue
         candidates.push({ type: 'mine', targetId: res.id, tileX: res.tileX, tileY: res.tileY, dist: dist(res.tileX, res.tileY), pri: p.mine })
       }
     }
@@ -397,7 +402,7 @@ export class VillagerSystem {
         this.claimed.delete(v.job.targetId)
         this.adapter.send({ type: 'VILLAGER_SET_JOB', villagerId: v.id, job: null })
       }
-      rt.idleScanTimer = 1500  // longer delay after failed pathfind
+      rt.idleScanTimer = 4000  // longer delay after failed pathfind to avoid tight retry loops
       return
     }
 
@@ -434,6 +439,22 @@ export class VillagerSystem {
     return this.nearestBuilding(v, 'bed') as any
   }
 
+  /**
+   * Returns true if at least one of the 8 neighbours of the given tile is passable.
+   * Used to pre-filter job targets that are fully enclosed by impassable terrain —
+   * such as trees deep inside a dense forest cluster where A* can never reach the goal
+   * tile because no passable tile is adjacent to it.
+   * @param tileX - Target tile X
+   * @param tileY - Target tile Y
+   */
+  private hasAdjacentPassable(tileX: number, tileY: number): boolean {
+    const DIRS = [[1,0],[-1,0],[0,1],[0,-1],[1,1],[1,-1],[-1,1],[-1,-1]] as const
+    for (const [dx, dy] of DIRS) {
+      if (this.worldSystem.isPassable(tileX + dx, tileY + dy)) return true
+    }
+    return false
+  }
+
   // ─── Spawning ─────────────────────────────────────────────────────────────
 
   /**