♻️(collaboration) switch collaboration server from hocuspocus to yhub

Signed-off-by: Kevin Jahns <kevin.jahns@protonmail.com>

docker/files/yhub/initdb/01-yhub.sql

@@ -0,0 +1,14 @@
+-- Column-for-column from yhub bin/init-db.js (unquoted identifiers so
+-- case-folding matches yhub's persistence.js queries).
+CREATE TABLE IF NOT EXISTS yhub_ydoc_v1 (
+    org             text,
+    docid           text,
+    branch          text,
+    t               text,
+    created         INT8,
+    gcDoc           bytea,
+    nongcDoc        bytea,
+    contentmap      bytea,
+    contentids      bytea,
+    PRIMARY KEY     (org,docid,branch,t)
+);