Add basic database schema migration system

PluralKit.Core/db_schema.sql

@@ -1,112 +0,0 @@
--- Create proxy_tag compound type if it doesn't exist
-do $$ begin
-    create type proxy_tag as (
-        prefix text,
-        suffix text
-    );
-exception when duplicate_object then null;
-end $$;
-
-create table if not exists systems
-(
-    id          serial primary key,
-    hid         char(5) unique not null,
-    name        text,
-    description text,
-    tag         text,
-    avatar_url  text,
-    token       text,
-    created     timestamp      not null default (current_timestamp at time zone 'utc'),
-    ui_tz       text           not null default 'UTC'
-);
-
-create table if not exists system_guild
-(
-    system serial not null references systems (id) on delete cascade,
-    guild bigint not null,
-    
-    proxy_enabled bool not null default true,
-    
-    primary key (system, guild)
-);
-
-create table if not exists members
-(
-    id           serial primary key,
-    hid          char(5) unique not null,
-    system       serial         not null references systems (id) on delete cascade,
-    color        char(6),
-    avatar_url   text,
-    name         text           not null,
-    display_name text,
-    birthday     date,
-    pronouns     text,
-    description  text,
-    proxy_tags   proxy_tag[]    not null default array[]::proxy_tag[], -- Rationale on making this an array rather than a separate table - we never need to query them individually, only access them as part of a selected Member struct
-    keep_proxy   bool           not null default false, 
-    created      timestamp      not null default (current_timestamp at time zone 'utc')
-);
-
-create table if not exists member_guild
-(
-    member serial not null references members (id) on delete cascade,
-    guild bigint not null,
-    
-    display_name text default null,
-    
-    primary key (member, guild)
-);
-
-create table if not exists accounts
-(
-    uid    bigint primary key,
-    system serial not null references systems (id) on delete cascade
-);
-
-create table if not exists messages
-(
-    mid          bigint primary key,
-    channel      bigint not null,
-    member       serial not null references members (id) on delete cascade,
-    sender       bigint not null,
-    original_mid bigint
-);
-
-create table if not exists switches
-(
-    id        serial primary key,
-    system    serial    not null references systems (id) on delete cascade,
-    timestamp timestamp not null default (current_timestamp at time zone 'utc')
-);
-CREATE INDEX IF NOT EXISTS idx_switches_system
-ON switches USING btree (
-	system ASC NULLS LAST
-) INCLUDE ("timestamp");
-
-create table if not exists switch_members
-(
-    id     serial primary key,
-    switch serial not null references switches (id) on delete cascade,
-    member serial not null references members (id) on delete cascade
-);
-CREATE INDEX IF NOT EXISTS idx_switch_members_switch
-ON switch_members USING btree (
-	switch ASC NULLS LAST
-) INCLUDE (member);
-
-create index if not exists idx_message_member on messages (member);
-
-create table if not exists webhooks
-(
-    channel bigint primary key,
-    webhook bigint not null,
-    token   text   not null
-);
-
-create table if not exists servers
-(
-    id            bigint primary key,
-    log_channel   bigint,
-    log_blacklist bigint[] not null default array[]::bigint[],
-    blacklist     bigint[] not null default array[]::bigint[] 
-);