refactor: remove generatedAt timestamp from API JSON output

Remove generation timestamp from API documentation JSON files to
eliminate unnecessary Git diff noise when regenerating docs.

- Remove generatedAt field from PackageDoc and ApiDocsIndex types
- Remove timestamp generation in generate-api-docs.ts script
- Remove footer timestamp display in api-markdown.ts
- Update tests to remove generatedAt references

This makes API doc generation idempotent - same input produces
identical output, improving CI/CD reliability.

Author: lambdalisue

lib/api-docs.ts

@@ -330,15 +330,11 @@ export interface PackageDoc {
   moduleDoc?: string;
   /** Exported items */
   exports: DocNode[];
-  /** Generation timestamp */
-  generatedAt: string;
 }
 
 export interface ApiDocsIndex {
   /** All packages */
   packages: PackageInfo[];
-  /** Generation timestamp */
-  generatedAt: string;
 }
 
 export interface ExportCounts {

lib/api-markdown.test.ts

@@ -25,7 +25,6 @@ function createPackageDoc(overrides: Partial<PackageDoc> = {}): PackageDoc {
     specifier: "@probitas/test-package",
     version: "1.0.0",
     exports: [],
-    generatedAt: "2024-01-01T00:00:00Z",
     ...overrides,
   };
 }
@@ -490,15 +489,6 @@ Deno.test("generateApiMarkdown - generates local type links", () => {
   assertStringIncludes(result, "`Config`");
 });
 
-Deno.test("generateApiMarkdown - includes generation timestamp", () => {
-  const pkg = createPackageDoc({
-    generatedAt: "2024-03-15T10:30:00Z",
-  });
-  const result = generateApiMarkdown(pkg);
-
-  assertStringIncludes(result, "*Generated at: 2024-03-15T10:30:00Z*");
-});
-
 Deno.test("generateApiMarkdown - includes examples from JSDoc", () => {
   const pkg = createPackageDoc({
     exports: [

lib/api-markdown.ts

@@ -738,10 +738,5 @@ export function generateApiMarkdown(
     }
   }
 
-  // Footer
-  lines.push("---");
-  lines.push("");
-  lines.push(`*Generated at: ${pkg.generatedAt}*`);
-
   return lines.join("\n");
 }

scripts/generate-api-docs.ts

@@ -134,7 +134,6 @@ async function generatePackageDoc(pkg: JsrPackage): Promise<PackageDoc | null> {
     version: pkg.latestVersion,
     moduleDoc,
     exports,
-    generatedAt: new Date().toISOString(),
   };
 }
 
@@ -156,7 +155,6 @@ async function savePackageDoc(doc: PackageDoc): Promise<void> {
 async function saveIndex(packages: PackageInfo[]): Promise<void> {
   const index: ApiDocsIndex = {
     packages,
-    generatedAt: new Date().toISOString(),
   };
 
   const filename = new URL("index.json", API_DIR);