chore: add issue templates with integration criteria (refs #2)

Adds Gitea issue templates to prevent missed integration points:
- feature.yaml: Includes Integration Criteria section for navigation,
  routing, and state management requirements
- bug.yaml: Structured bug reporting with platform selection
- chore.yaml: Technical debt and maintenance tasks

The Integration Criteria section ensures features specify:
- Desktop sidebar / mobile nav placement
- Route paths and default landing page
- Mobile screen type in navigation store

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.gitea/issue_template/bug.yaml

@@ -0,0 +1,85 @@
+name: Bug Report
+about: Report a bug or unexpected behavior
+title: "[Bug]: "
+labels:
+  - type/bug
+  - status/backlog
+body:
+  - type: markdown
+    attributes:
+      value: |
+        ## Bug Report
+        Use this template to report bugs. Provide as much detail as possible to help reproduce the issue.
+
+  - type: dropdown
+    id: platform
+    attributes:
+      label: Platform
+      description: Where did you encounter this bug?
+      options:
+        - Mobile (iOS)
+        - Mobile (Android)
+        - Desktop (Chrome)
+        - Desktop (Firefox)
+        - Desktop (Safari)
+        - Desktop (Edge)
+        - Multiple platforms
+    validations:
+      required: true
+
+  - type: textarea
+    id: description
+    attributes:
+      label: Bug Description
+      description: What went wrong? Be specific.
+      placeholder: "When I click X, I expected Y to happen, but instead Z happened."
+    validations:
+      required: true
+
+  - type: textarea
+    id: steps
+    attributes:
+      label: Steps to Reproduce
+      description: How can we reproduce this bug?
+      placeholder: |
+        1. Navigate to '...'
+        2. Click on '...'
+        3. Scroll down to '...'
+        4. See error
+    validations:
+      required: true
+
+  - type: textarea
+    id: expected
+    attributes:
+      label: Expected Behavior
+      description: What should have happened?
+    validations:
+      required: true
+
+  - type: textarea
+    id: actual
+    attributes:
+      label: Actual Behavior
+      description: What actually happened?
+    validations:
+      required: true
+
+  - type: textarea
+    id: context
+    attributes:
+      label: Additional Context
+      description: Screenshots, error messages, console logs, etc.
+    validations:
+      required: false
+
+  - type: textarea
+    id: fix-hints
+    attributes:
+      label: Fix Hints (if known)
+      description: Any ideas on what might be causing this or how to fix it?
+      placeholder: |
+        - Might be related to: [file or component]
+        - Similar issue in: [other feature]
+    validations:
+      required: false