fix: the declarations of the published package import the other declarations by their .js names.

build.mjs

@@ -4,7 +4,7 @@
 // the font plugin's virtual module, README.md, CHANGELOG.md and a package.json whose exports name the compiled files.
 
 import { spawnSync } from 'node:child_process';
-import { copyFileSync, readFileSync, rmSync, writeFileSync } from 'node:fs';
+import { copyFileSync, readdirSync, readFileSync, rmSync, writeFileSync } from 'node:fs';
 import { join } from 'node:path';
 
 const ROOT = import.meta.dirname;
@@ -21,6 +21,14 @@ const tsc = spawnSync(join(ROOT, 'node_modules', '.bin', 'tsc'), ['-p', join(ROO
 if (tsc.error) fail(`tsc: ${tsc.error.message}; run npm ci first`);
 if (tsc.status !== 0) process.exit(tsc.status ?? 1);
 
+// The declarations import the other declarations by their .js names, as the compiled JavaScript does.
+for (const entry of ENTRIES) {
+  for (const file of readdirSync(join(DIST, entry)).filter((name) => name.endsWith('.d.ts'))) {
+    const path = join(DIST, entry, file);
+    writeFileSync(path, readFileSync(path, 'utf8').replace(/(from\s+|import\s+)(['"])(\.{1,2}\/[^'"]+)\.tsx?\2/g, '$1$2$3.js$2'));
+  }
+}
+
 // The compiled renderApp keeps its import of virtual:font, so its declarations reference the module's declaration.
 copyFileSync(join(ROOT, 'web', 'virtual-font.d.ts'), join(DIST, 'web', 'virtual-font.d.ts'));
 const renderApp = join(DIST, 'web', 'renderApp.d.ts');