Fix varregion scene capture and legacy rendering

docs/grid-agent-operations.md

@@ -53,6 +53,10 @@ the default file is used only when it already exists:
 Relative paths in a YAML document resolve relative to that document where specified; service
 deployments should use absolute paths.
 
+Downloaded grid assets use the platform cache directory: `$XDG_CACHE_HOME/metacrate`
+or `$HOME/.cache/metacrate` on Linux, `$HOME/Library/Caches/metacrate` on macOS,
+and `%LOCALAPPDATA%\metacrate\cache` on Windows.
+
 ## Endpoint, grid identity, and authority
 
 `llm.endpoint_url` is the OpenAI-compatible provider base URL. Mentra owns the
@@ -226,10 +230,11 @@ The example records all current queue, message, conversation, tool, behavior,
 reconnect, and interaction defaults. Important defaults include 256 grid events,
 32 control commands, 512 observations, four concurrent inference requests,
 16 tool calls, 512 active senders/sessions, a two-minute model window, and bounded
-10-second shutdown. Vision defaults to a 640x360 headless Bevy/wgpu JPEG, a
-64-meter configurable view radius, a persistent 512 MiB decoded-texture cache,
-and a deterministic software fallback with bounded entities, triangles, asset
-work, JPEG bytes, time, and concurrency. Authorized `behavior_camera_set` calls are
+10-second shutdown. Vision defaults to a 1920x1080 headless Bevy/wgpu JPEG, a
+64-meter configurable view radius, a bounded in-memory decoded-texture cache,
+a persistent platform asset cache, and a deterministic software fallback with
+bounded entities, triangles, asset work, JPEG bytes, time, and concurrency.
+Authorized `behavior_camera_set` calls are
 limited to 96 meters from the avatar by default, require a distinct target, and
 accept a 20-120 degree vertical field of view; `behavior_camera_reset` restores
 the avatar-facing 60-degree view.