docs: add GitHub issue templates (bug report + feature request)

Adds a config.yml chooser and two markdown templates:
- bug_report.md — structured bug report with reproduction steps,
  environment info, and screenshot slot
- feature_request.md — enhancement/UX/refactor request with
  problem statement, proposed solution, and alternatives

Both follow the project's bracket-prefix title convention.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,33 @@
+---
+name: ✨ Feature request
+description: Suggest an idea, enhancement, UX improvement, or refactor
+title: '[enhancement] '
+labels: enhancement
+assignees: ''
+---
+
+## Problem / motivation
+
+<!--
+  What problem would this solve? Why is this needed?
+  e.g. "It's frustrating when …" or "The app currently lacks …"
+-->
+
+## Proposed solution
+
+<!-- A clear description of what you want to happen. -->
+
+## Alternative approaches
+
+<!-- Any alternative solutions or features you've considered. -->
+
+## Screenshots / mockups
+
+<!-- If applicable, add sketches, screenshots from other apps, or wireframes. -->
+
+## Additional context
+
+<!--
+  Any other details: links to similar features in other apps, relevant issues,
+  API endpoints that would be consumed, etc.
+-->