feat: file blocks

Moderators block a file network-wide by its sha256, from a product's files or the console's new Blocks tab, which
first shows the products using it. Blocking removes those products (their creators are told and may appeal), puts
a `block` change in the changes feed of every catalog hosting it, and refuses uploads with it; moderators see who
tried. Unblocking lets it in again; the products it removed stay removed until restored.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

packages/db/drizzle/meta/_journal.json

@@ -92,6 +92,13 @@
       "when": 1793888724185,
       "tag": "0012_cases",
       "breakpoints": true
+    },
+    {
+      "idx": 13,
+      "version": "7",
+      "when": 1793917069600,
+      "tag": "0013_file_blocks",
+      "breakpoints": true
     }
   ]
 }