Phase 3: strong flyers only spawn in high-level zones

- tools/zone_spawns.py: a species ridable through the air with top
  speed >= 60 or top stamina >= 85 never spawns in a zone whose band
  starts below Lv 30; lines that start as one are only placed in such
  zones, and the tool refuses to write pools that break the rule.
  Drampa moves to Sunscorch; Aerodactyl is fossil-only; Salamence never
  spawns wild (Bagon and Shelgon stay in the Dripstone caves).
- Ride stats stay Cobblemon's until play-tested (species_additions can
  override riding later).
- Phase 3 checklist: all steps in, approval checkpoint for Adrian.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tools/zone_spawns.py

@@ -21,7 +21,8 @@ datapacks/core/data/cobblesurvival/spawn_pool_world/<zone>.json:
      doesn't spawn there. If no stage fits, the closest one spawns across the whole band.
   3. world/zones.json → "species" pins a line to a zone by hand: {"pikachu": "southwold"}.
   4. In cave zones, sky-light minimums, "can see sky" and the "natural" ground preset are dropped.
-  5. Each zone with a "guardian" gets datapacks/core/data/cobblesurvival/guardians/<zone>.json: the
+  5. Strong flyers (STRONG_FLYER_*) only spawn in zones whose band starts at HIGH_ZONE_LEVEL or more.
+  6. Each zone with a "guardian" gets datapacks/core/data/cobblesurvival/guardians/<zone>.json: the
      strongest Pokémon spawning in the zone (or "species"), uncatchable, half again as big, five levels
      above the band, with the zone's boss drops and world/zones.json → guardian_respawn_hours.
 
@@ -54,6 +55,13 @@ MIN_CELLS = 5  # a zone "has" a biome when at least this many grid cells of it l
 # tags): its biomes say nothing about a home, so it only goes to a land zone, by strength. Its cave and
 # water entries still spawn underground and in the rivers of that zone.
 ALL_ROUNDER = 0.8
+# Roadmap Phase 3: strong flyers only spawn in high-level zones. A species you can ride through the air with a top
+# flying speed or stamina this high never spawns in a zone whose band starts below HIGH_ZONE_LEVEL (its weaker
+# pre-evolutions still do), and a line that starts as one is placed in such a zone only; if none fits its habitat,
+# it doesn't spawn in the wild.
+STRONG_FLYER_SPEED = 60
+STRONG_FLYER_STAMINA = 85
+HIGH_ZONE_LEVEL = 30
 
 
 def cobblemon_jar():
@@ -98,16 +106,23 @@ def zone_biomes(plan, layout, preview):
     return shares
 
 
-def base_stat_totals(jar):
-    """{species id: base-stat total} from Cobblemon's species files."""
-    totals = {}
+def species_data(jar):
+    """({species id: base-stat total}, {species ids that are strong flyers}) from Cobblemon's species files."""
+    totals, flyers = {}, set()
     with zipfile.ZipFile(jar) as z:
         for name in z.namelist():
             m = re.fullmatch(r"data/cobblemon/species/[^/]+/([^/]+)\.json", name)
-            if m:
-                stats = json.loads(z.read(name)).get("baseStats", {})
-                totals[f"cobblemon:{m[1]}"] = sum(stats.values())
-    return totals
+            if not m:
+                continue
+            data = json.loads(z.read(name))
+            totals[f"cobblemon:{m[1]}"] = sum(data.get("baseStats", {}).values())
+            air = ((data.get("riding") or {}).get("behaviours") or {}).get("AIR") or {}
+            stats = air.get("stats", {})
+            def top(stat):
+                return int(str(stats.get(stat, "0")).split("-")[-1])
+            if air and (top("SPEED") >= STRONG_FLYER_SPEED or top("STAMINA") >= STRONG_FLYER_STAMINA):
+                flyers.add(f"cobblemon:{m[1]}")
+    return totals, flyers
 
 
 def load_before(zone, room, stretch, target):
@@ -132,7 +147,7 @@ def main():
     species = guide["species"]
     jar = cobblemon_jar()
     entries = load_entries(jar)
-    bst = base_stat_totals(jar)
+    bst, strong_flyers = species_data(jar)
 
     zones = {z["id"]: z for z in plan["zones"]} | {c["id"]: c for c in plan["caves"]}
     shares = zone_biomes(plan, layout, preview)
@@ -161,6 +176,10 @@ def main():
         lines[line_root(member, species)].append((entry, set(s["biomes"]), member, s["level"]))
 
     pinned = {f"cobblemon:{k}" if ":" not in k else k: v for k, v in plan.get("species", {}).items()}
+    flying_lines = {root for root in lines if root in strong_flyers}
+
+    def allowed(root, zid):
+        return root not in flying_lines or zones[zid]["levels"][0] >= HIGH_ZONE_LEVEL
     wanted = {zid: z.get("lines", 20) for zid, z in zones.items()}
     scale = len(lines) / sum(wanted.values())
     target = {zid: n * scale for zid, n in wanted.items()}
@@ -191,7 +210,7 @@ def main():
             fit = 1 - abs(rank[root] - tier[zid])
             return habitat * specific ** 0.5 * fit ** 2 / (1 + load[zid] / target[zid])
 
-        candidates = [zid for zid in zones if line_biomes & biomes_of[zid]]
+        candidates = [zid for zid in zones if line_biomes & biomes_of[zid] and allowed(root, zid)]
         if candidates:
             home[root] = max(candidates, key=score)
             load[home[root]] += 1
@@ -206,14 +225,21 @@ def main():
     for root in sorted(all_rounders, key=lambda r: rank[r]):
         while load[current] >= load_before(current, room, stretch, target) and current != by_tier[-1]:
             current = next(zone_iter)
-        home[root] = current
-        load[current] += 1
+        # A strong flyer skips ahead to the first high zone.
+        home[root] = current if allowed(root, current) else next((z for z in by_tier if allowed(root, z)), None)
+        if home[root] is None:
+            del home[root]
+            continue
+        load[home[root]] += 1
 
     pools = collections.defaultdict(list)
     report = collections.defaultdict(list)
     for root, zid in home.items():
         lo, hi = zones[zid]["levels"]
-        usable = [(e, b, m, lv) for e, b, m, lv in lines[root] if b & biomes_of[zid]]
+        high = zones[zid]["levels"][0] >= HIGH_ZONE_LEVEL
+        usable = [(e, b, m, lv) for e, b, m, lv in lines[root] if b & biomes_of[zid] and (high or m not in strong_flyers)]
+        if not usable:
+            continue
         fitting = [(e, m, max(lv[0], lo), min(lv[1], hi)) for e, b, m, lv in usable if lv[0] <= hi and lv[1] >= lo]
         if not fitting:
             # No stage reaches the band: the closest stage spawns across all of it.
@@ -238,6 +264,11 @@ def main():
         names = sorted({species[m]["name"] for _, m, _, _ in fitting})
         report[zid].append((species.get(root, {}).get("name", root), names))
 
+    low_flyers = [(zid, s["pokemon"]) for zid, spawns in pools.items() for s in spawns
+                  if zones[zid]["levels"][0] < HIGH_ZONE_LEVEL and f"cobblemon:{s['pokemon'].split()[0].lower()}" in strong_flyers]
+    if low_flyers:
+        sys.exit(f"strong flyers would spawn below Lv {HIGH_ZONE_LEVEL}: {low_flyers[:5]}")
+
     OUT.mkdir(parents=True, exist_ok=True)
     for old in OUT.glob("*.json"):
         old.unlink()
@@ -292,6 +323,9 @@ def main():
     REPORT.write_text("\n".join(lines_out) + "\n")
 
     unplaced = [r for r in lines if r not in home]
+    grounded = sorted(species.get(r, {}).get("name", r) for r in unplaced if r in flying_lines)
+    if grounded:
+        print(f"strong flyers kept out of the wild (no high zone fits their habitat): {', '.join(grounded)}")
     for zid, zone in zones.items():
         print(f"  {zone['name']:18s} {len(report.get(zid, [])):3d} lines  {len(pools.get(zid, [])):4d} spawn entries")
     print(f"{len(home)} lines placed, {len(unplaced)} with no matching zone; wrote {OUT.relative_to(ROOT)} and {REPORT.relative_to(ROOT)}")