feat(calendar-compact): polish + global not-prose opt-out support

CalendarCompact:
- denser layout (smaller padding/font/badge), header icon size-8
- icon stein-900 (black), subtle wald gradient background
- rounded-sm to match design tokens (was rounded-lg)
- list items link to linkTo + "#event-<slug>" anchor; <svelte:element>
  falls back to div when no linkTo is set
- not-prose on root so global content margins/list/link rules don't
  apply to the card subtree

blog-utils.resolveCalendarBlocks:
- when items array is empty, fall back to the full calendar_item pool
  (both default and compact variant get this) — saves editors from
  re-listing items on every page.

app.css: add `:where(:not(.not-prose *))` to .content p/h1-h4,
main a (link colour + underline), main ul/ol so subtrees marked
not-prose stop inheriting the global prose-like defaults.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/lib/iconify-mdi-subset.generated.json

@@ -96,6 +96,9 @@
     "calendar-plus": {
       "body": "<path fill=\"currentColor\" d=\"M19 19V8H5v11zM16 1h2v2h1a2 2 0 0 1 2 2v14c0 1.11-.89 2-2 2H5a2 2 0 0 1-2-2V5c0-1.11.89-2 2-2h1V1h2v2h8zm-5 8.5h2v3h3v2h-3v3h-2v-3H8v-2h3z\"/>"
     },
+    "calendar-month-outline": {
+      "body": "<path fill=\"currentColor\" d=\"M7 11h2v2H7zm14-6v14c0 1.11-.89 2-2 2H5a2 2 0 0 1-2-2V5c0-1.1.9-2 2-2h1V1h2v2h8V1h2v2h1a2 2 0 0 1 2 2M5 7h14V5H5zm14 12V9H5v10zm-4-6v-2h2v2zm-4 0v-2h2v2zm-4 2h2v2H7zm8 2v-2h2v2zm-4 0v-2h2v2z\"/>"
+    },
     "arrow-right": {
       "body": "<path fill=\"currentColor\" d=\"M4 11v2h12l-5.5 5.5l1.42 1.42L19.84 12l-7.92-7.92L10.5 5.5L16 11z\"/>"
     },