Let a super admin read the database from the app

A new super admin settings page, /admin/settings/database, lists every
table with its record count and size, and one page of the open table's
records newest key first. Values are cut inside SQL (400 characters, with
a flag saying so) and a record opens whole in a modal, so a table of long
texts reads without shipping it all. A search matches every column's
text, word by word or as a phrase, which is the one thing that also works
on a virtual table. Nothing in it writes: the catalog, the records and
the single record are all reads, GET only.

src/functions/backend/database/to-database-cell.ts

@@ -0,0 +1,48 @@
+import formatBytes from "@/src/utils/format-bytes";
+import type { DatabaseCell } from "@/src/types";
+
+type Params = {
+    /**
+     * The value read out of SQLite, already cut to the length asked for.
+     */
+    value: unknown;
+    /**
+     * SQLite's own type for the stored value: `integer`, `real`, `text`,
+     * `blob` or `null`.
+     */
+    type: string;
+    /**
+     * How long the stored value is (characters for text, bytes for a
+     * blob), which says whether `value` is the whole of it.
+     */
+    length: number;
+    max_chars: number;
+};
+
+/**
+ * One stored value as a cell shows it. Text is cut at `max_chars` and
+ * marked truncated, a blob is only its size (its bytes would fill the page
+ * with noise), a number is printed as it is, and NULL is said, never left
+ * blank.
+ */
+export default function toDatabaseCell({ value, type, length, max_chars }: Params): DatabaseCell {
+    if (type == "null" || value === null || value === undefined) {
+        return { text: "", kind: "null", truncated: false };
+    }
+
+    if (type == "blob") {
+        return {
+            text: `<${formatBytes({ bytes: length })} of binary data>`,
+            kind: "blob",
+            truncated: false,
+        };
+    }
+
+    const text = String(value);
+
+    if (type == "integer" || type == "real") {
+        return { text, kind: "number", truncated: false };
+    }
+
+    return { text, kind: "text", truncated: length > max_chars };
+}