ci(workflow): add path filters to CI workflow (#15)

Only trigger builds when relevant files change:
- src/** (SDK and template source)
- samples/** (sample extension)
- .github/workflows/ci.yml (workflow itself)

Prevents unnecessary builds from documentation changes.

Author: CalvinAllen

.github/workflows/ci.yml

@@ -3,8 +3,16 @@ name: CI
 on:
   push:
     branches: [main]
+    paths:
+      - 'src/**'
+      - 'samples/**'
+      - '.github/workflows/ci.yml'
   pull_request:
     branches: [main]
+    paths:
+      - 'src/**'
+      - 'samples/**'
+      - '.github/workflows/ci.yml'
 
 jobs:
   build: