chore: add GitHub issue templates and improve PR template

Add YAML-based issue templates for bug reports and feature requests,
and restructure the PR template with summary, checklist, and type of change sections.

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

Author: kawaaaas

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,104 @@
+name: Bug Report
+description: Report a bug or unexpected behavior
+labels: ['bug']
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for taking the time to report a bug!
+
+  - type: input
+    id: version
+    attributes:
+      label: Package Version
+      description: Which version of `serverless-spa-construct` are you using?
+      placeholder: e.g. 0.1.0
+    validations:
+      required: true
+
+  - type: input
+    id: cdk-version
+    attributes:
+      label: AWS CDK Version
+      description: Which version of `aws-cdk-lib` are you using?
+      placeholder: e.g. 2.189.1
+    validations:
+      required: true
+
+  - type: dropdown
+    id: construct
+    attributes:
+      label: Affected Construct
+      description: Which construct is affected?
+      multiple: true
+      options:
+        - ServerlessSpaConstruct
+        - ServerlessSpaSecurityConstruct
+        - DatabaseConstruct
+        - AuthConstruct
+        - ApiConstruct
+        - FrontendConstruct
+        - WafConstruct
+        - CertificateConstruct
+        - SecretConstruct
+        - LambdaEdgeConstruct
+        - SsmConstruct
+        - Other
+    validations:
+      required: true
+
+  - type: dropdown
+    id: factory-method
+    attributes:
+      label: Factory Method (if applicable)
+      description: Which factory method are you using?
+      options:
+        - N/A (using low-level constructs)
+        - minimal()
+        - withWaf()
+        - withCustomDomain()
+        - withCustomDomainAndWaf()
+        - withCertificate()
+        - withWafAndCertificate()
+
+  - type: textarea
+    id: description
+    attributes:
+      label: Description
+      description: A clear description of the bug.
+    validations:
+      required: true
+
+  - type: textarea
+    id: reproduction
+    attributes:
+      label: Steps to Reproduce
+      description: Minimal code or steps to reproduce the issue.
+      placeholder: |
+        1. Create a stack with ...
+        2. Run `cdk synth` or `cdk deploy`
+        3. See error ...
+    validations:
+      required: true
+
+  - type: textarea
+    id: expected
+    attributes:
+      label: Expected Behavior
+      description: What did you expect to happen?
+    validations:
+      required: true
+
+  - type: textarea
+    id: actual
+    attributes:
+      label: Actual Behavior
+      description: What actually happened? Include error messages or CloudFormation errors if applicable.
+    validations:
+      required: true
+
+  - type: textarea
+    id: additional
+    attributes:
+      label: Additional Context
+      description: Any additional context, stack traces, or screenshots.

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1 @@
+blank_issues_enabled: true

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -0,0 +1,64 @@
+name: Feature Request
+description: Suggest a new feature or improvement
+labels: ['enhancement']
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for suggesting a feature!
+
+  - type: dropdown
+    id: area
+    attributes:
+      label: Area
+      description: Which area does this feature relate to?
+      multiple: true
+      options:
+        - ServerlessSpaConstruct (high-level)
+        - ServerlessSpaSecurityConstruct (high-level)
+        - Database / DynamoDB
+        - Auth / Cognito
+        - API Gateway / Lambda
+        - Frontend / CloudFront / S3
+        - WAF
+        - Certificate / ACM
+        - Secret / Secrets Manager
+        - Lambda@Edge
+        - SSM Parameter Store
+        - Documentation
+        - Other
+    validations:
+      required: true
+
+  - type: textarea
+    id: problem
+    attributes:
+      label: Problem
+      description: What problem does this feature solve? What use case is not currently supported?
+    validations:
+      required: true
+
+  - type: textarea
+    id: solution
+    attributes:
+      label: Proposed Solution
+      description: How do you think this should work? Include example API or code snippets if possible.
+      placeholder: |
+        ```ts
+        // Example of desired API
+        ServerlessSpaConstruct.minimal(this, "App", {
+          // ...
+        });
+        ```
+
+  - type: textarea
+    id: alternatives
+    attributes:
+      label: Alternatives Considered
+      description: Are there other approaches you've considered or workarounds you're currently using?
+
+  - type: textarea
+    id: additional
+    attributes:
+      label: Additional Context
+      description: Any additional context, references, or screenshots.