feat(frontends,conversations,telegram): the agent can hand a file to the human

src/beaver_gateway/settings.py

@@ -57,6 +57,10 @@ class Settings(BaseSettings):
     """``Accept-Language`` sent to the Raycast API and the default locale for
     auto ``UserPreferences``. One value per gateway (one shared Client)."""
 
+    send_file_roots: str = "/mnt/hole/shared"
+    """Directories the ``send_file`` tool may read, separated by ``:``. A
+    frontend always adds the inbox its own attachments land in."""
+
     bootstrap_tokens: str = ""
     """Out-of-band token seed: ``name1:value1,name2:value2``. Layers
     alongside DB-issued tokens; used for first-run setup and recovery."""