Replaces the ___ separator for FastMCPApp backend tool routing with a
deterministic hash(app_name, tool_name) prefix, and replaces the shared
singleton prefab renderer resource with per-tool resources synthesized
on demand.
Backend tools are now callable via <hash>_<local_name> instead of
<app_name>___<local_name>. The dispatcher walks the provider tree
recursively via get_tool_by_hash (same pattern as get_app_tool).
Each prefab tool gets its own renderer resource at
ui://prefab/tool/<hash>/renderer.html with per-tool CSP — fixing the
bug where PrefabAppConfig(csp=...) never actually applied.
Closes#3735, closes#3805
The store_files tool checked the client-provided `size` field to enforce
max_file_size, but this field is untrusted input. A client could set
size=1 while sending a multi-megabyte payload, bypassing the limit.
Now computes actual size from the base64 data length instead.
🤖 Generated with Claude Code
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>