chore: materialize canonical issue forms

Author: coenttb

.github/ISSUE_TEMPLATE/bug.yml

@@ -0,0 +1,50 @@
+name: Bug report
+description: Report reproducible incorrect behavior in this repository.
+title: ""
+type: Bug
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Do not report security vulnerabilities here. Use the private security-reporting link in the template chooser.
+  - type: textarea
+    id: behavior
+    attributes:
+      label: Observed behavior
+      description: What happened?
+    validations:
+      required: true
+  - type: textarea
+    id: expected
+    attributes:
+      label: Expected behavior
+      description: What should have happened?
+    validations:
+      required: true
+  - type: textarea
+    id: reproduction
+    attributes:
+      label: Minimal reproduction
+      description: Provide the smallest complete example and exact commands.
+      render: swift
+    validations:
+      required: true
+  - type: input
+    id: swift
+    attributes:
+      label: Swift version
+      placeholder: Output of swift --version
+    validations:
+      required: true
+  - type: input
+    id: platform
+    attributes:
+      label: Platform
+      placeholder: Operating system, architecture, and relevant SDK
+    validations:
+      required: true
+  - type: textarea
+    id: context
+    attributes:
+      label: Additional context
+      description: Add logs, links, or constraints that help reproduce the problem.

.github/ISSUE_TEMPLATE/change.yml

@@ -0,0 +1,37 @@
+name: Change request
+description: Propose a concrete change owned by this repository.
+title: ""
+type: Feature
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Use the discussion hub for open-ended exploration. File this form when the requested outcome is actionable.
+  - type: textarea
+    id: problem
+    attributes:
+      label: Problem
+      description: What user or implementation problem needs to be solved?
+    validations:
+      required: true
+  - type: textarea
+    id: outcome
+    attributes:
+      label: Proposed outcome
+      description: Describe the observable result, not only an implementation.
+    validations:
+      required: true
+  - type: textarea
+    id: alternatives
+    attributes:
+      label: Alternatives considered
+      description: What other approaches were evaluated?
+    validations:
+      required: true
+  - type: textarea
+    id: impact
+    attributes:
+      label: Compatibility and migration impact
+      description: Identify affected APIs, packages, platforms, or adopters.
+    validations:
+      required: true

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,8 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Report a security vulnerability
+    url: https://github.com/swift-foundations/swift-pdf/security/advisories/new
+    about: Privately report a vulnerability in this repository.
+  - name: Questions, proposals, and research
+    url: https://github.com/orgs/swift-institute/discussions
+    about: Use the Institute discussion hub for non-actionable questions and early design work.

.github/ISSUE_TEMPLATE/documentation.yml

@@ -0,0 +1,31 @@
+name: Documentation request
+description: Report missing, inaccurate, or unclear documentation.
+title: ""
+type: Task
+body:
+  - type: textarea
+    id: gap
+    attributes:
+      label: Documentation gap
+      description: What is missing, inaccurate, or unclear?
+    validations:
+      required: true
+  - type: input
+    id: location
+    attributes:
+      label: Location
+      description: Link to the affected README, DocC page, declaration, or example.
+    validations:
+      required: true
+  - type: textarea
+    id: proposed
+    attributes:
+      label: Proposed correction
+      description: Describe the change and the reader outcome it should produce.
+    validations:
+      required: true
+  - type: textarea
+    id: evidence
+    attributes:
+      label: Supporting evidence
+      description: Add source links, reproductions, or references that establish the correction.