fix: align agent lint with convert.sh and CI (#333)

Expands CI lint workflow to trigger on academic/ changes. Hardens lint-agents.sh with file existence checks and portable word-count handling (macOS/BSD compatibility).

.github/workflows/lint-agents.yml

@@ -3,18 +3,19 @@ name: Lint Agent Files
 on:
   pull_request:
     paths:
-      - 'design/**'
-      - 'engineering/**'
-      - 'game-development/**'
-      - 'marketing/**'
-      - 'paid-media/**'
-      - 'sales/**'
-      - 'product/**'
-      - 'project-management/**'
-      - 'testing/**'
-      - 'support/**'
-      - 'spatial-computing/**'
-      - 'specialized/**'
+      - "academic/**"
+      - "design/**"
+      - "engineering/**"
+      - "game-development/**"
+      - "marketing/**"
+      - "paid-media/**"
+      - "sales/**"
+      - "product/**"
+      - "project-management/**"
+      - "testing/**"
+      - "support/**"
+      - "spatial-computing/**"
+      - "specialized/**"
 
 jobs:
   lint:
@@ -29,7 +30,7 @@ jobs:
         id: changed
         run: |
           FILES=$(git diff --name-only --diff-filter=ACMR origin/${{ github.base_ref }}...HEAD -- \
-            'design/**/*.md' 'engineering/**/*.md' 'game-development/**/*.md' 'marketing/**/*.md' 'paid-media/**/*.md' 'sales/**/*.md' 'product/**/*.md' \
+            'academic/**/*.md' 'design/**/*.md' 'engineering/**/*.md' 'game-development/**/*.md' 'marketing/**/*.md' 'paid-media/**/*.md' 'sales/**/*.md' 'product/**/*.md' \
             'project-management/**/*.md' 'testing/**/*.md' 'support/**/*.md' \
             'spatial-computing/**/*.md' 'specialized/**/*.md')
           {