server

README.md

@@ -114,3 +114,76 @@ Open `index.html` in a modern browser. No build step or third-party dependency i
 - Coast foam uses two slow-rotating porous bluish-white layers.
 - Depth now affects phase-aware sprite shading for sun/moon exposure.
 - Added toggles for lights, particles, and the day-night cycle.
+
+
+## Phase 5 UI / particle follow-up
+- Coastal foam no longer uses cut-out holes.
+- Walking particles are less frequent and use more visibly varied colors.
+- Remix always creates a new derivative asset; Edit updates the user's own original asset.
+- Advanced Draw now includes configurable particle emitter cells for any asset.
+- PNG export/import moved to the Data tab.
+- Nudge arrow buttons under the canvas were removed; keyboard arrow nudging remains.
+- UI text is larger overall, while palette color-code labels keep their small size.
+
+## Rotation policy build
+
+This build adds count-based island rotation.
+
+- Default island display cap: 250 objects.
+- The local display cap is adjustable from Data > Visual settings.
+- Objects are not deleted when the cap is exceeded; the effective oldest objects are omitted from the island display.
+- Upvotes delay rotation-out by slot adjustment. Downvotes advance rotation-out.
+- Local publish / republish quota: 5 objects per author per rolling hour.
+- Replacing or republishing a rotation-hidden object updates its `publishedAt` and consumes one quota slot.
+
+Server-side periodic rotation code is in `server/rotation_worker.py`.
+
+Example:
+
+```bash
+python server/rotation_worker.py world.json --write
+```
+
+It performs:
+
+1. Permanent-hide marking for extremely downvoted objects.
+2. Randomly samples 50 hidden historical objects.
+3. Republishes the top 20 by upvote count.
+4. Reapplies the active display cap.
+5. Adds permanent-hidden objects to `adminReviewQueue` for deletion checks.
+
+
+## Local-only rotation note
+This build does not call a server from the browser. The island display cap is applied client-side, and objects over the cap are kept in local save but not drawn. Server recirculation / permanent hiding only happens when `server/rotation_worker.py` is run against exported world JSON.
+
+## Exhibition Policy Revision
+
+This build separates **Asset** and **PlacementObject** more explicitly.
+
+- Asset: a durable library work. Remix only copies pixels and lineage into the canvas.
+- PlacementObject: a temporary island exhibition object. It can rotate out while the Asset remains in Library.
+- Edit has been removed. To revise a work, remix/copy it, save a new Asset, then delete the old one if desired.
+- Publishing requires a prototype local account. The first 24 hours allow 5 public placements/hour; day 2+ allows 10/hour.
+- The island exhibition has 250 visible slots: 150 newest slots and 100 random revival slots.
+- Upvote rank effect is capped at +50 votes.
+- Capacity rotation and extreme downvote rotation use the same user-facing explanation: the island exhibition is full, but the work remains in Library.
+- Server moderation can mark `permanent_hidden` / `violation_hidden`; these are hidden from authors and viewers. Admins can restore them with the Python worker.
+- Particles are disabled offscreen/when zoomed out and capped at 200 active particles.
+
+### Server worker
+
+```bash
+python server/rotation_worker.py world.json --write
+python server/rotation_worker.py world.json --restore object123 --write
+python server/rotation_worker.py world.json --hide-violation object123 --write
+```
+
+The Python worker is the authoritative production policy. The browser mirrors it only for local prototype use.
+
+### Compression lab
+
+```bash
+python server/compression_lab.py exported_world.json
+```
+
+Use this to compare minified JSON, gzip, zlib, and Brotli when available. Production should use the compact asset codec plus HTTP gzip/Brotli rather than hand-rolled custom compression first.

index.html

@@ -11,6 +11,11 @@
     <canvas id="worldCanvas" aria-label="Island map"></canvas>
 
     <button id="openEditor" class="edgeAdd" title="Open Pixel Studio">+</button>
+    <div id="placementPreviewBar" class="placementPreviewBar" hidden>
+      <button id="confirmPreviewPlace" class="primary" type="button">Place here</button>
+      <button id="backToCanvas" class="secondary" type="button">Back to canvas</button>
+      <span>Check how this work looks on the island. Works are permanent in Library; island placement is temporary exhibition.</span>
+    </div>
 
     <header class="hud topHud">
       <div>
@@ -20,6 +25,8 @@
       <label class="authorCard">
         <span>Your Name</span>
         <input id="authorName" type="text" maxlength="24" value="Local Artist" />
+        <button id="createAccount" class="miniButton" type="button">Create local account</button>
+        <small id="accountNote">Account required to publish. Prototype only: name + local timestamp.</small>
       </label>
       <div class="clockCard" aria-label="world clock">
         <div id="phaseLabel" class="phaseLabel">Day</div>
@@ -111,37 +118,28 @@
               <button id="outlinePaint" class="tool" type="button">Outline</button>
               <button id="flipHorizontal" class="tool" type="button">Flip H</button>
               <button id="flipVertical" class="tool" type="button">Flip V</button>
-            </div>
-            <div class="toolRow editorMoveRow">
-              <button id="nudgeLeft" class="tool" type="button">←</button>
-              <button id="nudgeUp" class="tool" type="button">↑</button>
-              <button id="nudgeDown" class="tool" type="button">↓</button>
-              <button id="nudgeRight" class="tool" type="button">→</button>
               <button id="clearSelection" class="tool" type="button" disabled>Clear Sel</button>
             </div>
-            <div class="toolRow editorFileRow">
-              <button id="exportPng" class="tool" type="button">Export PNG</button>
-              <button id="importPng" class="tool" type="button">Import PNG</button>
-              <input id="pngImportInput" type="file" accept="image/png,image/*" hidden />
-            </div>
             <div class="advancedRow">
               <button id="toggleAdvanced" class="tool" type="button">Advanced Draw</button>
               <button id="toolLight" class="tool advancedOnly" hidden>Light</button>
               <button id="toolDepth" class="tool advancedOnly" hidden>Depth</button>
+              <button id="toolParticle" class="tool advancedOnly" hidden>Particle</button>
               <button id="depthHigh" class="tool advancedOnly" type="button" hidden>High</button>
               <button id="depthLow" class="tool advancedOnly" type="button" hidden>Low</button>
               <button id="depthClear" class="tool advancedOnly" type="button" hidden>Clear</button>
-              <span id="advancedHint" class="hint" hidden>Light/Depth tools are here. Depth supports High/Low/Clear. Left-drag paints the selected depth value; Shift clears.</span>
+              <span id="advancedHint" class="hint" hidden>Light, Particle, and Depth tools are here. Particle uses the selected palette color; Shift/right-click clears.</span>
             </div>
             <input id="paintColor" type="color" value="#6bd06b" hidden />
-            <div id="editHint" class="hint">Palette color is used for pixels, lights, and depth marks. Shortcuts: B/E/F/I/L/R/S, Ctrl/Cmd+Z, arrows move a selection.</div>
+            <div id="editHint" class="hint">Palette color is used for pixels, lights, particles, and depth marks. Shortcuts: B/E/F/I/L/R/S, Ctrl/Cmd+Z, arrows move a selection.</div>
           </div>
 
           <div class="card stack summonCard">
             <div class="cardTitle">Finish</div>
             <div class="actionRow finishActions">
-              <button id="saveAndPlace" class="primary bigPrimary">Save + Summon on Map</button>
-              <button id="saveAsset" class="secondary">Save only</button>
+              <button id="saveAndPlace" class="primary bigPrimary">Save + Place on Island</button>
+              <button id="saveAsset" class="secondary">Save to Library</button>
+              <button id="checkOnIsland" class="secondary">Check on Island</button>
               <button id="newAsset" class="secondary">New</button>
             </div>
           </div>
@@ -154,11 +152,12 @@
               <div class="cardTitle">Library</div>
               <button id="showHiddenAssets" class="tool" type="button">Hidden</button>
             </div>
-            <p class="hint">Click an asset to select it and jump to it on the map. Copy Edit creates a new derivative.</p>
+            <p class="hint">Your works are permanent here. The island is a temporary exhibition: place your own new or past works; remix only copies lineage and pixels to the canvas.</p>
             <div id="hiddenAssetPanel" class="hiddenAssetPanel" hidden>
               <div class="cardTitle">Hidden</div>
               <div id="hiddenAssetList" class="assetList compactAssetList"></div>
             </div>
+            <div id="likedCodex" class="likedCodex"></div>
             <div id="assetList" class="assetList"></div>
           </div>
         </section>
@@ -166,13 +165,16 @@
         <section id="tab-data" class="tabPanel">
           <div class="card stack">
             <div class="cardTitle">Local save</div>
-            <p class="hint">Saved to this browser only. Export JSON if you want to move or share a local world.</p>
+            <p class="hint">Works are durable library assets; island placements are temporary exhibition objects. Export JSON if you want to move or test a local world.</p>
             <div class="actionRow wrap">
               <button id="exportData">Export full JSON</button>
               <button id="exportCompact">Export compact</button>
               <button id="exportSnapshot">Export snapshot</button>
               <button id="exportAssetBundle">Export asset bundle</button>
               <button id="importData">Import JSON</button>
+              <button id="exportPng" type="button">Export PNG</button>
+              <button id="importPng" type="button">Import PNG</button>
+              <input id="pngImportInput" type="file" accept="image/png,image/*" hidden />
               <button id="resetAll" class="danger">Reset all</button>
             </div>
             <div id="syncStats" class="syncStats"></div>
@@ -182,12 +184,16 @@
 
           <div class="card stack">
             <div class="cardTitle">Visual settings</div>
-            <p class="hint">Turn major visual systems on or off.</p>
+            <p class="hint">Turn major visual systems on or off. Server decides the public 250 exhibition slots; this local cap only filters your view.</p>
             <div class="toggleList">
               <label class="checkRow"><input id="settingLights" type="checkbox" checked /> <span>Lights & glow</span></label>
               <label class="checkRow"><input id="settingParticles" type="checkbox" checked /> <span>Particles & ambient FX</span></label>
               <label class="checkRow"><input id="settingDayNight" type="checkbox" checked /> <span>Day / night cycle</span></label>
+              <label class="field displayLimitField">Island display cap
+                <input id="displayLimit" type="number" min="25" max="500" step="25" value="250" />
+              </label>
             </div>
+            <div id="rotationStats" class="syncStats"></div>
           </div>
 
           <div class="card stack">

js/phase2-sync.js

@@ -115,9 +115,13 @@
     const lights = Array.isArray(asset.meta?.lightPixels)
       ? asset.meta.lightPixels.map((p) => [Number(p.x) || 0, Number(p.y) || 0, p.c || asset.meta?.lightColor || '']).filter((p) => p[2])
       : [];
+    const particles = Array.isArray(asset.meta?.particlePixels)
+      ? asset.meta.particlePixels.map((p) => [Number(p.x) || 0, Number(p.y) || 0, p.c || '']).filter((p) => p[2])
+      : [];
     const meta = {};
     if (depth && /[1\-]/.test(depth)) meta.d = cropPlane(depth, size, '.');
     if (lights.length) meta.l = lights;
+    if (particles.length) meta.pt = particles;
     if (asset.meta?.lightColor) meta.lc = asset.meta.lightColor;
     if (asset.meta?.door) meta.dr = [Number(asset.meta.door.x) || 0, Number(asset.meta.door.y) || 0];
 
@@ -148,10 +152,15 @@
     const lightPixels = Array.isArray(metaPacked.l)
       ? metaPacked.l.map((p) => ({ x: Number(p[0]) || 0, y: Number(p[1]) || 0, c: p[2] || metaPacked.lc || 'a' }))
       : [];
+    const particlePixels = Array.isArray(metaPacked.pt)
+      ? metaPacked.pt.map((p) => ({ x: Number(p[0]) || 0, y: Number(p[1]) || 0, c: p[2] || 'a' }))
+      : [];
     const meta = {
       hasLight: lightPixels.length > 0,
       lightPixels,
       lightColor: lightPixels.length > 0 ? (metaPacked.lc || lightPixels[0]?.c || null) : null,
+      hasParticles: particlePixels.length > 0,
+      particlePixels,
       depthPixels: metaPacked.d ? expandPlane(metaPacked.d, size, '.') : null,
       door: Array.isArray(metaPacked.dr) ? { x: Number(metaPacked.dr[0]) || 0, y: Number(metaPacked.dr[1]) || 0 } : null
     };
@@ -174,21 +183,29 @@
   }
 
   function packPlacement(item) {
-    return [item.id, item.assetId, Number(item.x) || 0, Number(item.y) || 0, item.placedAt || Date.now(), Number(item.version) || 1];
+    const meta = {};
+    if (item.publishedAt) meta.pu = item.publishedAt;
+    if (item.status && item.status !== 'active') meta.st = item.status;
+    return [item.id, item.assetId, Number(item.x) || 0, Number(item.y) || 0, item.placedAt || Date.now(), Number(item.version) || 1, Object.keys(meta).length ? meta : null];
   }
 
   function unpackPlacement(row) {
     if (!Array.isArray(row)) return row;
-    return { id: row[0], assetId: row[1], x: row[2], y: row[3], placedAt: row[4], version: row[5] || 1 };
+    const meta = row[6] || {};
+    return { id: row[0], assetId: row[1], x: row[2], y: row[3], placedAt: row[4], version: row[5] || 1, publishedAt: meta.pu || row[4], status: meta.st || 'active' };
   }
 
   function packDynamic(item) {
-    return [item.id, item.assetId, Number(item.homeX) || 0, Number(item.homeY) || 0, item.createdAt || Date.now(), Number(item.version) || 1];
+    const meta = {};
+    if (item.publishedAt) meta.pu = item.publishedAt;
+    if (item.status && item.status !== 'active') meta.st = item.status;
+    return [item.id, item.assetId, Number(item.homeX) || 0, Number(item.homeY) || 0, item.createdAt || Date.now(), Number(item.version) || 1, Object.keys(meta).length ? meta : null];
   }
 
   function unpackDynamic(row) {
     if (!Array.isArray(row)) return row;
-    return { id: row[0], assetId: row[1], homeX: row[2], homeY: row[3], createdAt: row[4], version: row[5] || 1 };
+    const meta = row[6] || {};
+    return { id: row[0], assetId: row[1], homeX: row[2], homeY: row[3], createdAt: row[4], version: row[5] || 1, publishedAt: meta.pu || row[4], status: meta.st || 'active' };
   }
 
   function compactState(state) {
@@ -206,6 +223,8 @@
       moderationReports: Array.isArray(state.moderationReports) ? state.moderationReports : [],
       guardrails: state.guardrails || null,
       settings: state.settings || null,
+      account: state.account || null,
+      publishLog: Array.isArray(state.publishLog) ? state.publishLog.slice(-300) : [],
       eventLog: Array.isArray(state.eventLog) ? state.eventLog.slice(-EVENT_LOG_LIMIT) : [],
       sync: state.sync || { lastEventId: null }
     };
@@ -226,6 +245,8 @@
       moderationReports: Array.isArray(input.moderationReports) ? input.moderationReports : [],
       guardrails: input.guardrails || null,
       settings: input.settings || null,
+      account: input.account || null,
+      publishLog: Array.isArray(input.publishLog) ? input.publishLog.slice(-300) : [],
       eventLog: Array.isArray(input.eventLog) ? input.eventLog.slice(-EVENT_LOG_LIMIT) : [],
       sync: input.sync || { lastEventId: null }
     };

server/compression_lab.py

@@ -0,0 +1,42 @@
+#!/usr/bin/env python3
+"""Compare stronger compression candidates for Pixel Island asset JSON.
+
+Usage:
+  python server/compression_lab.py exported_world.json
+
+This does not change production data. It reports approximate sizes for raw JSON,
+minified JSON, gzip, zlib, and brotli if the optional `brotli` module is installed.
+For browser/server interchange, prefer: compact JSON -> gzip/brotli at HTTP layer.
+"""
+from __future__ import annotations
+import argparse, gzip, json, zlib
+from pathlib import Path
+
+try:
+    import brotli  # type: ignore
+except Exception:  # pragma: no cover
+    brotli = None
+
+
+def main() -> int:
+    ap = argparse.ArgumentParser()
+    ap.add_argument('json_file', type=Path)
+    args = ap.parse_args()
+    data = json.loads(args.json_file.read_text(encoding='utf-8'))
+    pretty = json.dumps(data, ensure_ascii=False, indent=2).encode('utf-8')
+    mini = json.dumps(data, ensure_ascii=False, separators=(',', ':')).encode('utf-8')
+    rows = [
+        ('pretty_json', len(pretty)),
+        ('minified_json', len(mini)),
+        ('gzip_9', len(gzip.compress(mini, compresslevel=9))),
+        ('zlib_9', len(zlib.compress(mini, level=9))),
+    ]
+    if brotli:
+        rows.append(('brotli_11', len(brotli.compress(mini, quality=11))))
+    base = len(pretty) or 1
+    for name, size in rows:
+        print(f'{name:14} {size:10d} bytes  {size/base:6.1%} of pretty JSON')
+    return 0
+
+if __name__ == '__main__':
+    raise SystemExit(main())

server/rotation_worker.py

@@ -0,0 +1,316 @@
+#!/usr/bin/env python3
+"""Authoritative server-side exhibition rotation policy for Pixel Island.
+
+This worker treats assets as permanent library works and placements as temporary
+island exhibition objects. The browser may preview the same policy locally, but
+production should accept this worker/database layer as the source of truth.
+
+Policy:
+- Account required to publish.
+- First 24h: 5 public placements/hour. Day 2+: 10 placements/hour.
+- Island exhibition cap: 250 active objects.
+- 150 slots are newest/recent-publication slots.
+- 100 slots are random revival slots.
+- Newest and revival buckets are selected independently; duplicates are removed.
+- Upvote rank effect is capped at +50 votes.
+- Downvotes advance rotation-out. Extreme downvote hides use the same user-facing
+  wording as capacity rotation, unless an admin marks a violation.
+- Reports are local-user hides in the client. Server-side moderation creates
+  permanent_hidden / violation_hidden only after admin/policy action.
+- permanent_hidden can be restored by an admin.
+"""
+from __future__ import annotations
+
+import argparse
+import json
+import random
+import time
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Any, Dict, Iterable, List, MutableMapping, Optional, Tuple
+
+DISPLAY_LIMIT = 250
+NEWEST_SLOTS = 150
+REVIVAL_SLOTS = 100
+REVIVAL_SAMPLE_SIZE = 50
+REVIVAL_PICK_COUNT = 20
+UPVOTE_DELAY_SLOTS = 20
+DOWNVOTE_ADVANCE_SLOTS = 25
+UPVOTE_RANK_CAP = 50
+FIRST_DAY_LIMIT = 5
+TRUSTED_LIMIT = 10
+ONE_HOUR_MS = 60 * 60 * 1000
+ONE_DAY_MS = 24 * ONE_HOUR_MS
+EXTREME_DOWNVOTES = 10
+EXTREME_MARGIN = 8
+
+ACTIVE = "active"
+HIDDEN_ROTATION = "hidden_rotation"
+PERMANENT_HIDDEN = "permanent_hidden"
+VIOLATION_HIDDEN = "violation_hidden"
+
+PUBLIC_REASON_ROTATION = "island_exhibition_full"
+PUBLIC_REASON_VIOLATION = "moderation_violation"
+
+@dataclass
+class RotationConfig:
+    display_limit: int = DISPLAY_LIMIT
+    newest_slots: int = NEWEST_SLOTS
+    revival_slots: int = REVIVAL_SLOTS
+    revival_sample_size: int = REVIVAL_SAMPLE_SIZE
+    revival_pick_count: int = REVIVAL_PICK_COUNT
+    upvote_delay_slots: int = UPVOTE_DELAY_SLOTS
+    downvote_advance_slots: int = DOWNVOTE_ADVANCE_SLOTS
+    upvote_rank_cap: int = UPVOTE_RANK_CAP
+    extreme_downvotes: int = EXTREME_DOWNVOTES
+    extreme_margin: int = EXTREME_MARGIN
+
+
+def now_ms() -> int:
+    return int(time.time() * 1000)
+
+
+def object_id(obj: MutableMapping[str, Any]) -> str:
+    return str(obj.get("id") or "")
+
+
+def public_at(obj: MutableMapping[str, Any]) -> int:
+    return int(obj.get("publishedAt") or obj.get("placedAt") or obj.get("createdAt") or 0)
+
+
+def author_id_from_account(account: MutableMapping[str, Any] | None) -> str:
+    return str((account or {}).get("id") or "")
+
+
+def account_publish_limit(account: MutableMapping[str, Any] | None, now: Optional[int] = None) -> int:
+    if not account or not account.get("createdAt"):
+        return 0
+    now = now or now_ms()
+    created = int(account.get("createdAt") or now)
+    return FIRST_DAY_LIMIT if now - created < ONE_DAY_MS else TRUSTED_LIMIT
+
+
+def can_publish(state: MutableMapping[str, Any], account: MutableMapping[str, Any] | None, now: Optional[int] = None) -> Tuple[bool, Dict[str, Any]]:
+    """API helper. Production publish endpoints should call this before accepting a placement."""
+    now = now or now_ms()
+    account_id = author_id_from_account(account)
+    limit = account_publish_limit(account, now)
+    if not account_id or limit <= 0:
+        return False, {"reason": "account_required", "used": 0, "limit": 0}
+    log = [entry for entry in state.get("publishLog") or [] if now - int(entry.get("at") or 0) < ONE_DAY_MS]
+    used = sum(1 for entry in log if entry.get("author") == account_id and now - int(entry.get("at") or 0) < ONE_HOUR_MS)
+    state["publishLog"] = log
+    return used < limit, {"reason": None if used < limit else "quota_exceeded", "used": used, "limit": limit}
+
+
+def record_publish(state: MutableMapping[str, Any], account: MutableMapping[str, Any], obj: MutableMapping[str, Any], kind: str, action: str, now: Optional[int] = None) -> None:
+    now = now or now_ms()
+    obj["publishedAt"] = now
+    obj["status"] = ACTIVE
+    obj.pop("hiddenReason", None)
+    obj.pop("hiddenAt", None)
+    log = state.setdefault("publishLog", [])
+    log.append({"at": now, "author": author_id_from_account(account), "kind": kind, "objectId": object_id(obj), "assetId": obj.get("assetId"), "action": action})
+    state["publishLog"] = log[-10000:]
+
+
+def iter_objects(state: MutableMapping[str, Any]) -> Iterable[Tuple[str, MutableMapping[str, Any]]]:
+    for obj in state.get("placed") or []:
+        if isinstance(obj, MutableMapping) and obj.get("id"):
+            yield "static", obj
+    for obj in state.get("dynamicSummons") or []:
+        if isinstance(obj, MutableMapping) and obj.get("id"):
+            yield "dynamic", obj
+
+
+def vote_counts(state: MutableMapping[str, Any], obj_id: str) -> Tuple[int, int]:
+    votes = (state.get("objectVotes") or {}).get(obj_id) or {}
+    return int(votes.get("up") or 0), int(votes.get("down") or 0)
+
+
+def is_moderation_hidden(obj: MutableMapping[str, Any]) -> bool:
+    return obj.get("status") in {PERMANENT_HIDDEN, VIOLATION_HIDDEN} or obj.get("permanentHidden") is True
+
+
+def eligible_for_exhibition(obj: MutableMapping[str, Any]) -> bool:
+    return not is_moderation_hidden(obj)
+
+
+def rotation_entry(state: MutableMapping[str, Any], kind: str, obj: MutableMapping[str, Any], base_index: int, config: RotationConfig) -> Dict[str, Any]:
+    up_raw, down = vote_counts(state, object_id(obj))
+    up_rank = min(up_raw, config.upvote_rank_cap)
+    return {
+        "kind": kind,
+        "object": obj,
+        "id": object_id(obj),
+        "publicAt": public_at(obj),
+        "baseIndex": base_index,
+        "up": up_raw,
+        "upRank": up_rank,
+        "down": down,
+        "effectiveSlot": base_index + up_rank * config.upvote_delay_slots - down * config.downvote_advance_slots,
+    }
+
+
+def rotation_entries(state: MutableMapping[str, Any], config: RotationConfig) -> List[Dict[str, Any]]:
+    pairs = [(kind, obj) for kind, obj in iter_objects(state) if eligible_for_exhibition(obj)]
+    pairs.sort(key=lambda pair: (public_at(pair[1]), object_id(pair[1])))
+    return [rotation_entry(state, kind, obj, i, config) for i, (kind, obj) in enumerate(pairs)]
+
+
+def deterministic_random_score(obj_id: str, seed: int) -> float:
+    rng = random.Random(f"{seed}:{obj_id}")
+    return rng.random()
+
+
+def select_exhibition_buckets(state: MutableMapping[str, Any], config: RotationConfig, seed: Optional[int] = None) -> Dict[str, List[Dict[str, Any]]]:
+    seed = seed if seed is not None else int(state.get("lastRotationAt") or now_ms()) // ONE_DAY_MS
+    entries = rotation_entries(state, config)
+    newest = sorted(entries, key=lambda e: (e["effectiveSlot"], e["publicAt"], e["id"]), reverse=True)[:config.newest_slots]
+    newest_ids = {e["id"] for e in newest}
+    revival_pool = [e for e in entries if e["id"] not in newest_ids]
+
+    # Periodic server revival: sample up to 50 previous/excess objects, then take 20 with
+    # the best capped score, while keeping randomness in the sample.
+    historical = [e for e in revival_pool if e["object"].get("status") == HIDDEN_ROTATION]
+    rng = random.Random(seed)
+    sample = rng.sample(historical, min(config.revival_sample_size, len(historical))) if historical else []
+    picked = sorted(sample, key=lambda e: (e["upRank"], e["upRank"] - e["down"], e["publicAt"]), reverse=True)[:config.revival_pick_count]
+    picked_ids = {e["id"] for e in picked}
+
+    rest = [e for e in revival_pool if e["id"] not in picked_ids]
+    random_rest = sorted(rest, key=lambda e: (deterministic_random_score(e["id"], seed), e["upRank"] - e["down"]), reverse=True)
+    revival = (picked + random_rest)[:config.revival_slots]
+    return {"newest": newest, "revival": revival, "entries": entries}
+
+
+def apply_extreme_downvote_policy(state: MutableMapping[str, Any], config: RotationConfig, now: Optional[int] = None) -> List[Dict[str, Any]]:
+    """Hide extreme downvote cases from the island with the same public text as capacity rotation.
+
+    This is not a violation decision. It stays reversible and is separate from admin
+    violation hiding.
+    """
+    now = now or now_ms()
+    changed: List[Dict[str, Any]] = []
+    for kind, obj in iter_objects(state):
+        if is_moderation_hidden(obj):
+            continue
+        up, down = vote_counts(state, object_id(obj))
+        if down >= config.extreme_downvotes and down - up >= config.extreme_margin:
+            obj["status"] = HIDDEN_ROTATION
+            obj["hiddenReason"] = PUBLIC_REASON_ROTATION
+            obj["hiddenAt"] = now
+            changed.append({"objectId": object_id(obj), "assetId": obj.get("assetId"), "kind": kind, "reason": "extreme_downvotes_as_rotation", "up": up, "down": down})
+    return changed
+
+
+def apply_exhibition_cap(state: MutableMapping[str, Any], config: RotationConfig, seed: Optional[int] = None, now: Optional[int] = None) -> Dict[str, Any]:
+    now = now or now_ms()
+    buckets = select_exhibition_buckets(state, config, seed=seed)
+    visible_ids = {e["id"] for e in buckets["newest"] + buckets["revival"]}
+    newly_active = newly_hidden = 0
+    for entry in buckets["entries"]:
+        obj = entry["object"]
+        if entry["id"] in visible_ids:
+            if obj.get("status") != ACTIVE:
+                newly_active += 1
+            obj["status"] = ACTIVE
+            obj.pop("hiddenReason", None)
+            obj.pop("hiddenAt", None)
+        else:
+            if obj.get("status") != HIDDEN_ROTATION:
+                newly_hidden += 1
+            obj["status"] = HIDDEN_ROTATION
+            obj["hiddenReason"] = PUBLIC_REASON_ROTATION
+            obj["hiddenAt"] = now
+    return {"active": len(visible_ids), "newest": len(buckets["newest"]), "revival": len(buckets["revival"]), "rotationHidden": max(0, len(buckets["entries"]) - len(visible_ids)), "newlyActive": newly_active, "newlyHidden": newly_hidden}
+
+
+def hide_violation(state: MutableMapping[str, Any], object_ids: List[str], now: Optional[int] = None) -> List[str]:
+    now = now or now_ms()
+    hidden: List[str] = []
+    for _, obj in iter_objects(state):
+        if object_id(obj) in object_ids:
+            obj["status"] = VIOLATION_HIDDEN
+            obj["permanentHidden"] = True
+            obj["hiddenReason"] = PUBLIC_REASON_VIOLATION
+            obj["hiddenAt"] = now
+            hidden.append(object_id(obj))
+    return hidden
+
+
+def restore_permanent(state: MutableMapping[str, Any], object_ids: List[str], now: Optional[int] = None) -> List[str]:
+    """Admin restore for permanent/violation hidden placements."""
+    now = now or now_ms()
+    restored: List[str] = []
+    for _, obj in iter_objects(state):
+        if object_id(obj) in object_ids and is_moderation_hidden(obj):
+            obj["status"] = HIDDEN_ROTATION
+            obj["permanentHidden"] = False
+            obj["hiddenReason"] = PUBLIC_REASON_ROTATION
+            obj["hiddenAt"] = now
+            restored.append(object_id(obj))
+    return restored
+
+
+def run_rotation(state: MutableMapping[str, Any], config: RotationConfig, seed: Optional[int] = None) -> Dict[str, Any]:
+    now = now_ms()
+    extreme = apply_extreme_downvote_policy(state, config, now=now)
+    cap = apply_exhibition_cap(state, config, seed=seed, now=now)
+    state["lastRotationAt"] = now
+    state["rotationPolicy"] = {
+        "displayLimit": config.display_limit,
+        "newestSlots": config.newest_slots,
+        "revivalSlots": config.revival_slots,
+        "upvoteRankCap": config.upvote_rank_cap,
+        "serverAuthoritative": True,
+    }
+    return {"extremeDownvoteHiddenAsRotation": extreme, "cap": cap, "lastRotationAt": now}
+
+
+def load_json(path: Path) -> MutableMapping[str, Any]:
+    with path.open("r", encoding="utf-8") as f:
+        data = json.load(f)
+    if not isinstance(data, MutableMapping):
+        raise ValueError("World JSON root must be an object")
+    return data
+
+
+def save_json(path: Path, data: MutableMapping[str, Any]) -> None:
+    with path.open("w", encoding="utf-8") as f:
+        json.dump(data, f, ensure_ascii=False, separators=(",", ":"))
+
+
+def parse_args() -> argparse.Namespace:
+    parser = argparse.ArgumentParser(description="Run Pixel Island exhibition rotation policy on a world JSON file.")
+    parser.add_argument("world_json", type=Path)
+    parser.add_argument("--write", action="store_true")
+    parser.add_argument("--out", type=Path)
+    parser.add_argument("--seed", type=int)
+    parser.add_argument("--display-limit", type=int, default=DISPLAY_LIMIT)
+    parser.add_argument("--newest-slots", type=int, default=NEWEST_SLOTS)
+    parser.add_argument("--revival-slots", type=int, default=REVIVAL_SLOTS)
+    parser.add_argument("--restore", nargs="*", default=None, help="Admin restore object IDs from permanent/violation hidden to rotation hidden.")
+    parser.add_argument("--hide-violation", nargs="*", default=None, help="Admin hide object IDs as violation_hidden.")
+    return parser.parse_args()
+
+
+def main() -> int:
+    args = parse_args()
+    state = load_json(args.world_json)
+    config = RotationConfig(display_limit=args.display_limit, newest_slots=args.newest_slots, revival_slots=args.revival_slots)
+    summary: Dict[str, Any] = {}
+    if args.restore:
+        summary["restored"] = restore_permanent(state, args.restore)
+    if args.hide_violation:
+        summary["violationHidden"] = hide_violation(state, args.hide_violation)
+    if not args.restore and not args.hide_violation:
+        summary = run_rotation(state, config, seed=args.seed)
+    print(json.dumps(summary, ensure_ascii=False, indent=2))
+    if args.write or args.out:
+        save_json(args.out or args.world_json, state)
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

styles.css

@@ -968,3 +968,50 @@ body, button, input, select, textarea {
 .toggleList { display:flex; flex-direction:column; gap:10px; }
 .checkRow { display:flex; align-items:center; gap:10px; font-size:13px; color:#243044; }
 .checkRow input { width:16px; height:16px; }
+
+/* Phase 5 UI polish: larger readable controls while keeping palette code labels small. */
+body, button, input, select, textarea { font-size: 15px; }
+.logo { font-size: 24px; }
+.subline { font-size: 14px; }
+.authorCard span, .clockHint { font-size: 12px; }
+.phaseLabel { font-size: 14px; }
+.iconButton, .tool, .tab, button { font-size: 14px; line-height: 1.15; }
+.toolHud .iconButton { font-size: 14px; min-width: 74px; padding: 10px 12px; }
+.cardTitle { font-size: 17px; }
+.field, .hint, .lineageNote, .syncStats { font-size: 14px; line-height: 1.45; }
+.toolRow { gap: 8px; }
+.editorHistoryRow { grid-template-columns: repeat(6, minmax(0, 1fr)); }
+.advancedRow { grid-template-columns: repeat(6, max-content) 1fr; align-items: start; }
+.assetMeta strong { font-size: 16px; }
+.assetMeta span { font-size: 13px; }
+.assetActions button { font-size: 12px; padding: 6px 7px; }
+.selectionBubble { font-size: 14px; }
+.bubbleName { font-size: 15px; }
+.bubbleAuthor, .bubbleRemixFrom, .bubbleRemixCount { font-size: 12px; }
+.bubbleActions button, .bubbleVotes button { font-size: 12px; padding: 6px 8px; }
+.paletteGrid button, .paletteSwatch { font-size: 7px !important; }
+.checkRow { font-size: 14px; }
+@media (max-width: 760px) {
+  body, button, input, select, textarea { font-size: 14px; }
+  .toolHud .iconButton { min-width: 68px; }
+  .editorHistoryRow { grid-template-columns: repeat(3, minmax(0, 1fr)); }
+  .advancedRow { grid-template-columns: repeat(3, minmax(0, 1fr)); }
+}
+
+.displayLimitField input { font-size: 16px; min-height: 36px; width: 110px; }
+.rotationBadge { font-size: 13px; color: #4d5b72; }
+
+
+/* exhibition/account polish */
+.authorCard { min-width: 210px; }
+.authorCard small { display:block; margin-top:6px; font-size:12px; line-height:1.35; opacity:.82; }
+.miniButton { margin-top:6px; padding:6px 8px; border:2px solid #243044; background:#fff3d9; box-shadow:2px 2px 0 rgba(36,48,68,.22); cursor:pointer; font-size:12px; }
+.placementPreviewBar { position:fixed; left:50%; bottom:22px; transform:translateX(-50%); z-index:35; display:flex; align-items:center; gap:10px; max-width:min(760px, calc(100vw - 24px)); padding:12px 14px; border:3px solid #243044; background:#fff7de; box-shadow:5px 5px 0 rgba(36,48,68,.25); font-size:15px; }
+.placementPreviewBar[hidden] { display:none; }
+.likedCodex { margin:8px 0 14px; padding:10px; border:2px dashed rgba(36,48,68,.35); background:rgba(255,255,255,.45); font-size:14px; }
+.likedCodexTitle { font-weight:700; margin-bottom:6px; }
+.likedCodexList { display:flex; gap:8px; flex-wrap:wrap; }
+.likedCodexItem { display:flex; align-items:center; gap:6px; border:2px solid rgba(36,48,68,.25); background:#fffdf5; padding:4px 6px; max-width:180px; }
+.likedCodexItem canvas { width:28px; height:28px; image-rendering:pixelated; }
+.hiddenReasonText { color:#6f2f3b; font-weight:700; }
+.exhibitionNote { padding:8px 10px; background:#fff3d9; border:2px solid rgba(36,48,68,.2); margin-bottom:8px; font-size:14px; line-height:1.45; }