feat: add GitHub issue templates for bug, feature, and question

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -0,0 +1,26 @@
+name: Feature Request
+description: Suggest a new feature or improvement
+title: "[Feature] "
+labels: ["enhancement"]
+body:
+  - type: textarea
+    id: description
+    attributes:
+      label: Describe the feature
+      placeholder: A clear description of the feature you'd like.
+    validations:
+      required: true
+  - type: textarea
+    id: motivation
+    attributes:
+      label: Motivation
+      placeholder: Why do you want this? What problem does it solve?
+    validations:
+      required: false
+  - type: textarea
+    id: alternatives
+    attributes:
+      label: Alternatives considered
+      placeholder: Any alternative solutions or workarounds you've considered.
+    validations:
+      required: false