Handle missing ZXDB releases/downloads schema gracefully

Prevent runtime crashes when `releases`, `downloads`, or related lookup tables
(`releasetypes`, `schemetypes`, `sourcetypes`, `casetypes`) are absent in the
connected ZXDB MySQL database.

- Repo: gate releases/downloads queries behind a schema capability check using
  `information_schema.tables`; if missing, skip queries and return empty arrays.
- Keeps entry detail page functional on legacy/minimal DB exports while fully
  utilizing rich data when available.

Refs: runtime error "Table 'zxdb.releasetypes' doesn't exist"

Signed-off-by: Junie@quinn

src/server/schema/zxdb.ts

@@ -1,4 +1,4 @@
-import { mysqlTable, int, varchar, tinyint, char } from "drizzle-orm/mysql-core";
+import { mysqlTable, int, varchar, tinyint, char, smallint } from "drizzle-orm/mysql-core";
 
 // Minimal subset needed for browsing/searching
 export const entries = mysqlTable("entries", {
@@ -79,3 +79,91 @@ export const genretypes = mysqlTable("genretypes", {
   // Column name in DB is `text`
   name: varchar("text", { length: 50 }).notNull(),
 });
+
+// ----- Files and Filetypes (for downloads/assets) -----
+export const filetypes = mysqlTable("filetypes", {
+  id: tinyint("id").notNull().primaryKey(),
+  // Column name in DB is `text`
+  name: varchar("text", { length: 50 }).notNull(),
+});
+
+export const files = mysqlTable("files", {
+  id: int("id").notNull().primaryKey(),
+  labelId: int("label_id"),
+  issueId: int("issue_id"),
+  toolId: int("tool_id"),
+  fileLink: varchar("file_link", { length: 250 }).notNull(),
+  fileDate: varchar("file_date", { length: 50 }),
+  fileSize: int("file_size"),
+  fileMd5: varchar("file_md5", { length: 32 }),
+  filetypeId: tinyint("filetype_id").notNull(),
+  comments: varchar("comments", { length: 250 }),
+});
+
+// ----- Releases / Downloads (linked assets per release) -----
+// Lookups used by releases/downloads
+export const releasetypes = mysqlTable("releasetypes", {
+  id: char("id", { length: 1 }).notNull().primaryKey(),
+  // column name in DB is `text`
+  name: varchar("text", { length: 50 }).notNull(),
+});
+
+export const schemetypes = mysqlTable("schemetypes", {
+  id: char("id", { length: 2 }).notNull().primaryKey(),
+  name: varchar("text", { length: 50 }).notNull(),
+});
+
+export const sourcetypes = mysqlTable("sourcetypes", {
+  id: char("id", { length: 1 }).notNull().primaryKey(),
+  name: varchar("text", { length: 50 }).notNull(),
+});
+
+export const casetypes = mysqlTable("casetypes", {
+  id: char("id", { length: 1 }).notNull().primaryKey(),
+  name: varchar("text", { length: 50 }).notNull(),
+});
+
+export const hosts = mysqlTable("hosts", {
+  id: tinyint("id").notNull().primaryKey(),
+  title: varchar("title", { length: 150 }).notNull(),
+  link: varchar("link", { length: 150 }).notNull(),
+  admin: varchar("admin", { length: 150 }).notNull(),
+  magazineId: smallint("magazine_id"),
+});
+
+// `releases` are identified by (entry_id, release_seq)
+export const releases = mysqlTable("releases", {
+  entryId: int("entry_id").notNull(),
+  releaseSeq: smallint("release_seq").notNull(),
+  releasetypeId: char("releasetype_id", { length: 1 }),
+  languageId: char("language_id", { length: 2 }),
+  machinetypeId: tinyint("machinetype_id"),
+  labelId: int("label_id"), // developer
+  publisherId: int("publisher_label_id"),
+  releaseYear: smallint("release_year"),
+  comments: varchar("comments", { length: 250 }),
+});
+
+// Downloads are linked to a release via (entry_id, release_seq)
+export const downloads = mysqlTable("downloads", {
+  id: int("id").notNull().primaryKey(),
+  entryId: int("entry_id").notNull(),
+  releaseSeq: smallint("release_seq").notNull().default(0),
+  fileLink: varchar("file_link", { length: 250 }).notNull(),
+  fileDate: varchar("file_date", { length: 50 }),
+  fileSize: int("file_size"),
+  fileMd5: varchar("file_md5", { length: 32 }),
+  filetypeId: tinyint("filetype_id").notNull(),
+  scrBorder: tinyint("scr_border").notNull().default(7),
+  languageId: char("language_id", { length: 2 }),
+  isDemo: tinyint("is_demo").notNull(),
+  schemetypeId: char("schemetype_id", { length: 2 }),
+  machinetypeId: tinyint("machinetype_id"),
+  fileCode: varchar("file_code", { length: 50 }),
+  fileBarcode: varchar("file_barcode", { length: 50 }),
+  fileDl: varchar("file_dl", { length: 150 }),
+  casetypeId: char("casetype_id", { length: 1 }),
+  sourcetypeId: char("sourcetype_id", { length: 1 }),
+  releaseYear: smallint("release_year"),
+  comments: varchar("comments", { length: 250 }),
+});