Update ZXDB docs and notes

Document multi-select filters and shared explorer components.

Signed-off-by: codex@lucy.xalior.com

docs/ZXDB.md

@@ -76,6 +76,7 @@ All endpoints are under `/api/zxdb` and validate inputs with Zod. Responses are
     - `sort` — `title` or `id_desc`
     - `scope` — `title`, `title_aliases`, or `title_aliases_origins`
     - `facets` — boolean; if truthy, includes facet counts for genres/languages/machines
+    - `machinetypeId` accepts a comma‑separated list (e.g. `27,26,8,9`) for multi‑select filters
 
 - Entry detail
   - `GET /api/zxdb/entries/[id]`
@@ -90,6 +91,13 @@ All endpoints are under `/api/zxdb` and validate inputs with Zod. Responses are
   - `GET /api/zxdb/languages` and `/api/zxdb/languages/[id]?page=1`
   - `GET /api/zxdb/machinetypes` and `/api/zxdb/machinetypes/[id]?page=1`
 
+- Search releases
+  - `GET /api/zxdb/releases/search`
+  - Query params:
+    - `q`, `page`, `pageSize`, `year`, `sort` — as used in the releases explorer
+    - `dLanguageId`, `filetypeId`, `schemetypeId`, `sourcetypeId`, `casetypeId`, `isDemo`
+    - `dMachinetypeId` accepts a comma‑separated list for multi‑select filters
+
 Runtime: API routes declare `export const runtime = "nodejs"` to support `mysql2`.
 
 ## Implementation notes
@@ -103,6 +111,7 @@ Runtime: API routes declare `export const runtime = "nodejs"` to support `mysql2
   }
   ```
 - Repository queries parallelize independent calls with `Promise.all` for lower latency.
+- When no machine filter is provided, the explorer prefers machine IDs `27,26,8,9` for sorting.
 
 ## Troubleshooting