clean: remove CI debugging artifacts and testing features

- Remove test files: test-ghost-profile.md, test-local-deployment.sh, validate-ghost-extraction.sh, AGENTS.md
- Restore .gitlab-ci.yml to original state without debugging changes
- Restore _quarto.yml to original format without ghost profiles
- Remove ghost-iframe.css styling file
- Restore ghost-upload/.gitlab-ci.yml to original state without force-update job
- Simplify Rust code by removing force update functionality and content extraction
- Restore README.md to original state

Keeps core bug fixes: fixed get_slug() and proper Ghost API duplicate checking

_quarto.yml

@@ -1,42 +1,25 @@
 project:
   type: website
 
-profiles:
-  default:
-    website:
-      title: "Anson's Projects"
-      site-url: https://projects.ansonbiggs.com
-      description: A Blog for Technical Topics
-      navbar:
-        left:
-          - text: "About"
-            href: about.html
-        right:
-          - icon: rss
-            href: index.xml
-          # - icon: gitlab
-          #   href: https://gitlab.com/MisterBiggs
-      open-graph: true
-    format:
-      html:
-        theme: zephyr
-        css: styles.css
-        # toc: true
-  
-  ghost:
-    website:
-      title: "Anson's Projects"
-      site-url: https://projects.ansonbiggs.com
-      description: A Blog for Technical Topics
-      navbar: false
-      open-graph: true
-    format:
-      html:
-        theme: none
-        css: ghost-iframe.css
-        toc: false
-        page-layout: article
-        title-block-banner: false
+website:
+  title: "Anson's Projects"
+  site-url: https://projects.ansonbiggs.com
+  description: A Blog for Technical Topics
+  navbar:
+    left:
+      - text: "About"
+        href: about.html
+    right:
+      - icon: rss
+        href: index.xml
+      # - icon: gitlab
+      #   href: https://gitlab.com/MisterBiggs
+  open-graph: true
+format:
+  html:
+    theme: zephyr
+    css: styles.css
+    # toc: true
 
 execute: 
   freeze: true