refactor(courses): migrate instructor fields to use people collection references

- Updated `coursesCollection` schema in `src/content/config.ts` to type the `instructor` field as a `reference('people')`.
- Modified all course markdown entries to use person slugs (e.g., `lale-akarun`, `berk-gokberk`) instead of hardcoded strings.
- Refactored `courses.astro` and `courses/[slug].astro` templates to asynchronously resolve instructor references via `getEntry`.
- Added a `shortenTitle` helper to automatically abbreviate academic titles (e.g., "Assistant Professor" to "Asst. Prof.") on course views.

Author: kutayeroglu

src/content/config.ts

@@ -1,4 +1,4 @@
-import { defineCollection, z } from 'astro:content';
+import { defineCollection, reference, z } from 'astro:content';
 
 // Define the schema for the papers collection
 const papersCollection = defineCollection({
@@ -91,7 +91,7 @@ const coursesCollection = defineCollection({
   schema: z.object({
     title: z.string(),
     code: z.string(),
-    instructor: z.string(),
+    instructor: reference('people'),
     description: z.string().optional(),
     semester: z.string().optional(),
     credits: z.number().optional(),

src/content/courses/cmpe537-computer-vision.md

@@ -3,7 +3,7 @@ title: "Computer Vision"
 code: "CMPE 537"
 description: "Graduate computer vision: imaging and cameras, filtering and CNNs, segmentation, features, object and action recognition, motion, tracking, and 3D vision—with implementations and a term project."
 semester: "Fall 2025–2026"
-instructor: "Prof. Dr. Lale Akarun"
+instructor: "lale-akarun"
 credits: 3
 featured: true
 ---

src/content/courses/cmpe538-3d-computer-vision.md

@@ -1,5 +1,5 @@
 ---
 title: "3D Computer Vision"
 code: "CMPE 538"
-instructor: "Prof. Dr. Lale Akarun"
+instructor: "lale-akarun"
 ---

src/content/courses/cmpe58z-introduction-to-biometrics.md

@@ -1,5 +1,5 @@
 ---
 title: "Introduction to Biometrics"
 code: "CMPE 58Z"
-instructor: "Prof. Dr. Berk Gökberk"
+instructor: "berk-gokberk"
 ---

src/content/courses/cmpe593-deep-learning-computer-vision.md

@@ -3,7 +3,7 @@ title: "Deep Learning for Computer Vision"
 code: "CMPE 593"
 description: "Graduate course on applied deep learning for computer vision: convolutional networks, detection, segmentation, generative models, and vision transformers."
 semester: "Fall 2025–2026"
-instructor: "Prof. Dr. Berk Gökberk"
+instructor: "berk-gokberk"
 credits: 3
 syllabus: "https://registration.bogazici.edu.tr/scripts/instructor/coursedescriptions/2025-2026-1/CMPE59301.PDF"
 featured: true

src/pages/courses.astro

@@ -1,9 +1,25 @@
 ---
 import MainLayout from '../layouts/MainLayout.astro';
-import { getCollection } from 'astro:content';
+import { getCollection, getEntry } from 'astro:content';
 
 const courses = await getCollection('courses');
 courses.sort((a, b) => a.data.code.localeCompare(b.data.code));
+
+const coursesWithInstructors = await Promise.all(
+  courses.map(async (course) => {
+    const instructor = await getEntry(course.data.instructor);
+    return { ...course, instructorData: instructor?.data };
+  })
+);
+
+function shortenTitle(title?: string) {
+  if (!title) return '';
+  if (title === "Professor") return "Prof.";
+  if (title === "Assistant Professor") return "Asst. Prof.";
+  if (title === "Associate Professor") return "Assoc. Prof.";
+  return title;
+}
+
 const base = import.meta.env.BASE_URL;
 ---
 
@@ -12,7 +28,7 @@ const base = import.meta.env.BASE_URL;
     <h1 class="text-4xl font-bold text-primary mb-12 text-center">Courses</h1>
 
     <div class="max-w-2xl mx-auto space-y-4">
-      {courses.map((course) => (
+      {coursesWithInstructors.map((course) => (
         <div class="bg-white rounded-lg shadow-md px-6 py-4 flex flex-col sm:flex-row sm:items-start sm:justify-between gap-3">
           <div class="min-w-0 flex-1">
             <span class="text-sm font-medium text-primary">{course.data.code}</span>
@@ -25,7 +41,9 @@ const base = import.meta.env.BASE_URL;
               <p class="text-sm text-gray-600 mt-2 leading-relaxed">{course.data.description}</p>
             )}
           </div>
-          <p class="text-gray-600 sm:text-right sm:shrink-0">{course.data.instructor}</p>
+          <p class="text-gray-600 sm:text-right sm:shrink-0">
+            {course.instructorData ? `${shortenTitle(course.instructorData.title)} ${course.instructorData.name}` : ''}
+          </p>
         </div>
       ))}
     </div>

src/pages/courses/[slug].astro

@@ -1,6 +1,6 @@
 ---
 import MainLayout from '../../layouts/MainLayout.astro';
-import { getCollection } from 'astro:content';
+import { getCollection, getEntry } from 'astro:content';
 
 export async function getStaticPaths() {
   const courses = await getCollection('courses');
@@ -11,6 +11,17 @@ export async function getStaticPaths() {
 }
 
 const { course } = Astro.props;
+const instructor = await getEntry(course.data.instructor);
+const instructorData = instructor?.data;
+
+function shortenTitle(title?: string) {
+  if (!title) return '';
+  if (title === "Professor") return "Prof.";
+  if (title === "Assistant Professor") return "Asst. Prof.";
+  if (title === "Associate Professor") return "Assoc. Prof.";
+  return title;
+}
+
 const { Content } = await course.render();
 const base = import.meta.env.BASE_URL;
 ---
@@ -37,7 +48,7 @@ const base = import.meta.env.BASE_URL;
           </div>
 
           <div class="mb-8">
-            <p class="text-gray-600 mb-1"><span class="font-semibold">Instructor:</span> {course.data.instructor}</p>
+            <p class="text-gray-600 mb-1"><span class="font-semibold">Instructor:</span> {instructorData ? `${shortenTitle(instructorData.title)} ${instructorData.name}` : ''}</p>
             {course.data.semester != null && course.data.semester !== '' && (
               <p class="text-gray-600 mb-1"><span class="font-semibold">Semester:</span> {course.data.semester}</p>
             )}