Add agentic workflows page to website

Add a new /workflows/ page for browsing agentic workflow definitions
with search, trigger/tag filters, and sorting. Follows the same
patterns as the existing hooks page.

New files:
- website/src/pages/workflows.astro
- website/src/scripts/pages/workflows.ts

Updated files:
- BaseLayout.astro: add Workflows nav link
- index.astro: add Workflows card to homepage
- pages/index.ts: add workflows to counts
- utils.ts: add workflow type to icons, labels, and getResourceType

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

website/src/layouts/BaseLayout.astro

@@ -70,6 +70,10 @@ try {
               href={`${base}hooks/`}
               class:list={[{ active: activeNav === "hooks" }]}>Hooks</a
             >
+            <a
+              href={`${base}workflows/`}
+              class:list={[{ active: activeNav === "workflows" }]}>Workflows</a
+            >
             <a
               href={`${base}plugins/`}
               class:list={[{ active: activeNav === "plugins" }]}