Move readonly item property display values to server

client/public/version.js

@@ -1,5 +1,5 @@
 // Maintainer-controlled web client version.
 // Format: YYYY.MM.DD Rn (example: 2026.02.20 R2)
-window.CHGRID_WEB_VERSION = "2026.02.25 R275";
+window.CHGRID_WEB_VERSION = "2026.02.25 R276";
 // Optional display timezone for timestamps. Falls back to America/Detroit if unset/invalid.
 window.CHGRID_TIME_ZONE = "America/Detroit";

client/src/items/itemPropertyPresentation.ts

@@ -34,17 +34,7 @@ export function createItemPropertyPresentation(deps: PresentationDeps): {
 
   const getItemPropertyValue = (item: WorldItem, key: string): string => {
     if (key === 'title') return item.title;
-    if (key === 'type') return item.type;
+    if (item.display && typeof item.display[key] === 'string') return item.display[key];
-    if (key === 'x') return String(item.x);
-    if (key === 'y') return String(item.y);
-    if (key === 'carrierId') return item.carrierId ?? 'none';
-    if (key === 'version') return String(item.version);
-    if (key === 'createdBy') return item.createdBy;
-    if (key === 'createdAt') return deps.formatTimestampMs(item.createdAt);
-    if (key === 'updatedAt') return deps.formatTimestampMs(item.updatedAt);
-    if (key === 'capabilities') return item.capabilities.join(', ') || 'none';
-    if (key === 'useSound') return toSoundDisplayName(item.params.useSound ?? item.useSound);
-    if (key === 'emitSound') return toSoundDisplayName(item.params.emitSound ?? item.emitSound);
     const metadata = getItemPropertyMetadata(item.type, key);
     const globalValue = getItemTypeGlobalProperties(item.type)?.[key];
     const paramValue = item.params[key];
@@ -69,6 +59,17 @@ export function createItemPropertyPresentation(deps: PresentationDeps): {
     if (metadata?.valueType === 'list' || metadata?.valueType === 'text') {
       return rawValue === undefined || rawValue === null ? '' : String(rawValue);
     }
+    if (key === 'type') return item.type;
+    if (key === 'x') return String(item.x);
+    if (key === 'y') return String(item.y);
+    if (key === 'carrierId') return item.carrierId ?? 'none';
+    if (key === 'version') return String(item.version);
+    if (key === 'createdBy') return item.createdBy;
+    if (key === 'createdAt') return deps.formatTimestampMs(item.createdAt);
+    if (key === 'updatedAt') return deps.formatTimestampMs(item.updatedAt);
+    if (key === 'capabilities') return item.capabilities.join(', ') || 'none';
+    if (key === 'useSound') return toSoundDisplayName(item.params.useSound ?? item.useSound);
+    if (key === 'emitSound') return toSoundDisplayName(item.params.emitSound ?? item.emitSound);
     if (paramValue !== undefined) return String(paramValue);
     if (globalValue !== undefined) return String(globalValue);
     return '';

client/src/network/protocol.ts

@@ -15,6 +15,7 @@ export const itemSchema = z.object({
   emitSound: z.string().optional(),
   params: z.record(z.string(), z.unknown()),
   carrierId: z.string().nullable().optional(),
+  display: z.record(z.string(), z.string()).optional(),
 });
 
 export const welcomeMessageSchema = z.object({

client/src/state/gameState.ts

@@ -19,6 +19,7 @@ export type WorldItem = {
   emitSound?: string;
   params: Record<string, unknown>;
   carrierId?: string | null;
+  display?: Record<string, string>;
 };
 
 export type SelectionContext = 'pickup' | 'drop' | 'delete' | 'edit' | 'use' | 'secondaryUse' | 'inspect' | null;

docs/protocol-notes.md

@@ -46,6 +46,7 @@ This is a behavior guide for packet semantics beyond raw schemas.
 ## Item Packet Behavior
 
 - `item_upsert` is full-state replacement for one item, not partial patch.
+- `item_upsert.item.display` is server-owned display text for readonly/system properties (for example: `createdAt`, `updatedAt`, `capabilities`, `useSound`, `emitSound`).
 - `item_action_result` messages are intended for direct screen-reader/user status feedback.
 - Piano runtime control no longer depends on parsing `item_action_result.message` text.
 - `item_piano_status` carries machine-readable piano events (`use_mode_entered`, record/playback transitions).

server/app/models.py

@@ -251,6 +251,7 @@ class WorldItem(BaseModel):
     emitSound: str | None = None
     params: dict
     carrierId: str | None = None
+    display: dict[str, str] | None = None
 
 
 class PersistedWorldItem(BaseModel):

server/app/server.py

@@ -6,7 +6,7 @@ import argparse
 import asyncio
 from collections import deque
 from contextlib import suppress
-from datetime import datetime
+from datetime import datetime, timezone
 from getpass import getpass
 from importlib.metadata import PackageNotFoundError, version as package_version
 import json
@@ -355,6 +355,48 @@ class SignalingServer:
             return item.useSound.strip()
         return None
 
+    @staticmethod
+    def _format_display_sound_name(value: object) -> str:
+        """Return display-friendly sound token (file name only) for item property menus."""
+
+        raw = str(value or "").strip()
+        if not raw:
+            return "none"
+        if raw.lower() == "none":
+            return "none"
+        without_query = raw.split("?", 1)[0].split("#", 1)[0]
+        segments = [segment for segment in without_query.split("/") if segment]
+        return segments[-1] if segments else raw
+
+    @staticmethod
+    def _format_display_timestamp_ms(value: int) -> str:
+        """Format epoch milliseconds to compact UTC text used in item property menus."""
+
+        dt = datetime.fromtimestamp(value / 1000, tz=timezone.utc)
+        return dt.strftime("%Y-%m-%d %H:%M")
+
+    def _build_item_display_values(self, item: WorldItem) -> dict[str, str]:
+        """Build server-authoritative item property display values for readonly/system fields."""
+
+        return {
+            "type": item.type,
+            "x": str(item.x),
+            "y": str(item.y),
+            "carrierId": item.carrierId or "none",
+            "version": str(item.version),
+            "createdBy": item.createdBy,
+            "createdAt": self._format_display_timestamp_ms(item.createdAt),
+            "updatedAt": self._format_display_timestamp_ms(item.updatedAt),
+            "capabilities": ", ".join(item.capabilities) if item.capabilities else "none",
+            "useSound": self._format_display_sound_name(item.params.get("useSound", item.useSound)),
+            "emitSound": self._format_display_sound_name(item.params.get("emitSound", item.emitSound)),
+        }
+
+    def _outbound_item(self, item: WorldItem) -> WorldItem:
+        """Return one outbound item snapshot enriched with server-owned display values."""
+
+        return item.model_copy(update={"display": self._build_item_display_values(item)})
+
     def _get_item_emit_range(self, item: WorldItem) -> int:
         """Return effective emit range for one item with sane bounds."""
 
@@ -1023,7 +1065,7 @@ class SignalingServer:
     async def _broadcast_item(self, item: WorldItem) -> None:
         """Broadcast a full item snapshot update to all connected clients."""
 
-        await self._broadcast(ItemUpsertPacket(type="item_upsert", item=item))
+        await self._broadcast(ItemUpsertPacket(type="item_upsert", item=self._outbound_item(item)))
 
     async def start(self) -> None:
         """Start websocket serving and run until cancelled."""
@@ -1117,7 +1159,7 @@ class SignalingServer:
             id=client.id,
             player=RemoteUser(id=client.id, nickname=client.nickname, x=client.x, y=client.y),
             users=users,
-            items=[item.model_dump(exclude_none=True) for item in self.items.values()],
+            items=[self._outbound_item(item).model_dump(exclude_none=True) for item in self.items.values()],
             worldConfig={
                 "gridSize": self.grid_size,
                 "movementTickMs": self.movement_tick_ms,