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/chore.yaml

@@ -0,0 +1,70 @@
+name: Chore / Maintenance
+about: Technical debt, refactoring, dependency updates, infrastructure
+title: "[Chore]: "
+labels:
+  - type/chore
+  - status/backlog
+body:
+  - type: markdown
+    attributes:
+      value: |
+        ## Chore / Maintenance Task
+        Use this template for technical debt, refactoring, dependency updates, or infrastructure work.
+
+  - type: dropdown
+    id: category
+    attributes:
+      label: Category
+      description: What type of chore is this?
+      options:
+        - Refactoring
+        - Dependency update
+        - Performance optimization
+        - Technical debt cleanup
+        - Infrastructure / DevOps
+        - Testing improvements
+        - Documentation
+        - Other
+    validations:
+      required: true
+
+  - type: textarea
+    id: description
+    attributes:
+      label: Description
+      description: What needs to be done and why?
+      placeholder: "We need to refactor X because Y..."
+    validations:
+      required: true
+
+  - type: textarea
+    id: scope
+    attributes:
+      label: Scope / Files Affected
+      description: What parts of the codebase will be touched?
+      placeholder: |
+        - frontend/src/features/[name]/
+        - backend/src/features/[name]/
+        - docker-compose.yml
+    validations:
+      required: false
+
+  - type: textarea
+    id: acceptance
+    attributes:
+      label: Definition of Done
+      description: How do we know this is complete?
+      placeholder: |
+        - [ ] All tests pass
+        - [ ] No new linting errors
+        - [ ] Performance benchmark improved by X%
+    validations:
+      required: true
+
+  - type: textarea
+    id: risks
+    attributes:
+      label: Risks / Breaking Changes
+      description: Any potential issues or breaking changes to be aware of?
+    validations:
+      required: false