fix!: finally fix the dodgy postgate/threadgate foreign keys

diesel.toml

···
 [print_schema]
 file = "parakeet-db/src/schema.rs"
 custom_type_derives = ["diesel::query_builder::QueryId"]
+patch_file = "fk.patch"
 
 [migrations_directory]
 dir = "migrations"

fk.patch

···
+diff --git a/parakeet-db/src/schema.rs b/parakeet-db/src/schema.rs
+index 59f65d9..a4219d5 100644
+--- a/parakeet-db/src/schema.rs
++++ b/parakeet-db/src/schema.rs
+@@ -364,11 +364,13 @@ diesel::joinable!(post_embed_images -> posts (post_uri));
+ diesel::joinable!(post_embed_record -> posts (post_uri));
+ diesel::joinable!(post_embed_video -> posts (post_uri));
+ diesel::joinable!(post_embed_video_captions -> posts (post_uri));
++diesel::joinable!(postgates -> posts (post_uri));
+ diesel::joinable!(posts -> actors (did));
+ diesel::joinable!(profiles -> actors (did));
+ diesel::joinable!(reposts -> actors (did));
+ diesel::joinable!(starterpacks -> actors (owner));
+ diesel::joinable!(statuses -> actors (did));
++diesel::joinable!(threadgates -> posts (post_uri));
+ diesel::joinable!(verification -> actors (verifier));
+ 
+ diesel::allow_tables_to_appear_in_same_query!(

migrations/2025-02-16-142357_posts/up.sql

···
 (
     at_uri     text primary key,
     cid        text        not null,
-    post_uri   text        not null references posts (at_uri) on delete cascade deferrable,
+    post_uri   text        not null,
 
     detached   text[]      not null,
     rules      text[]      not null,
···
 (
     at_uri         text primary key,
     cid            text        not null,
-    post_uri       text        not null references posts (at_uri) on delete cascade deferrable,
+    post_uri       text        not null,
 
     hidden_replies text[]      not null,
     allow          text[]      not null,