feat(plugins): punktfunk-host plugins CLI — add/remove/list/enable/disable/status

One-liner plugin management replacing the manual scripting-dir + bunfig +
bun-add ritual: package ops forward to the bun runner (new sdk plugins
module + runner-cli subcommands, 11 tests green), enable/disable/status
drive the systemd unit on Linux and the PunktfunkScripting scheduled task
on Windows (installer support in the ISS). Docs page rewritten as .mdx
with per-platform Tabs (registered in mdx.tsx).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs-site/src/components/mdx.tsx

@@ -1,4 +1,5 @@
 import defaultMdxComponents from 'fumadocs-ui/mdx'
+import { Tab, Tabs } from 'fumadocs-ui/components/tabs'
 import type { MDXComponents } from 'mdx/types'
 import BitrateCalculator from '@/components/BitrateCalculator'
 
@@ -7,6 +8,9 @@ export function getMDXComponents(components?: MDXComponents) {
     ...defaultMdxComponents,
     // Custom components usable in any .md/.mdx without a per-file import.
     BitrateCalculator,
+    // Per-platform instructions: <Tabs items={['Linux', 'Windows']}><Tab value="Linux">…
+    Tabs,
+    Tab,
     ...components,
   } satisfies MDXComponents
 }