fix: address QA review findings

1. Typography: install @tailwindcss/typography and add to plugins so prose
   classes render correctly in article/about/legal templates.

2. Callout block: fix icon branches to match CalloutBlock.ICON_CHOICES
   (info/warning/trophy/tip). Previous template branched on error/success
   which are unreachable; info fell through to else silently.

3. Nav newsletter feedback: remove 'hidden' class from desktop nav
   data-newsletter-message element. JS sets textContent only; hidden
   class prevented message from ever being visible.

4. Popular Articles sidebar: add numbered Popular Articles widget to home
   page sidebar matching wireframe, using latest_articles context with
   alternating cyan/pink number accents and read_time_mins.

Rebuild CSS: typography plugin grows output from 24KB to 47KB.

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

theme/static_src/package-lock.json

@@ -8,6 +8,7 @@
       "name": "nohype-theme",
       "version": "1.0.0",
       "devDependencies": {
+        "@tailwindcss/typography": "^0.5.19",
         "tailwindcss": "^3.4.17"
       }
     },
@@ -93,6 +94,33 @@
         "node": ">= 8"
       }
     },
+    "node_modules/@tailwindcss/typography": {
+      "version": "0.5.19",
+      "resolved": "https://registry.npmjs.org/@tailwindcss/typography/-/typography-0.5.19.tgz",
+      "integrity": "sha512-w31dd8HOx3k9vPtcQh5QHP9GwKcgbMp87j58qi6xgiBnFFtKEAgCWnDw4qUT8aHwkCp8bKvb/KGKWWHedP0AAg==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "postcss-selector-parser": "6.0.10"
+      },
+      "peerDependencies": {
+        "tailwindcss": ">=3.0.0 || insiders || >=4.0.0-alpha.20 || >=4.0.0-beta.1"
+      }
+    },
+    "node_modules/@tailwindcss/typography/node_modules/postcss-selector-parser": {
+      "version": "6.0.10",
+      "resolved": "https://registry.npmjs.org/postcss-selector-parser/-/postcss-selector-parser-6.0.10.tgz",
+      "integrity": "sha512-IQ7TZdoaqbT+LCpShg46jnZVlhWD2w6iQYAcYXfHARZ7X1t/UGhhceQDs5X0cGqKvYlHNOuv7Oa1xmb0oQuA3w==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "cssesc": "^3.0.0",
+        "util-deprecate": "^1.0.2"
+      },
+      "engines": {
+        "node": ">=4"
+      }
+    },
     "node_modules/any-promise": {
       "version": "1.3.0",
       "resolved": "https://registry.npmjs.org/any-promise/-/any-promise-1.3.0.tgz",