DOC: Update docs for new tutorials, issues templates

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,67 @@
+name: Bug report
+description: Something isn't working as expected.
+labels: ["bug"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for taking the time to report a bug. See the
+        [Bug Reports](https://project-monai.github.io/physiotwin4d/contributing.html#bug-reports)
+        section of the contributing guide for what makes a good report.
+
+  - type: input
+    id: version
+    attributes:
+      label: PhysioTwin4D version
+      placeholder: "e.g. 2026.09.0, or a commit SHA if installed from source"
+    validations:
+      required: true
+
+  - type: input
+    id: python-version
+    attributes:
+      label: Python version
+      placeholder: "e.g. 3.12.4"
+    validations:
+      required: true
+
+  - type: input
+    id: os
+    attributes:
+      label: Operating system
+      placeholder: "e.g. Windows 11, Ubuntu 22.04"
+    validations:
+      required: true
+
+  - type: input
+    id: gpu
+    attributes:
+      label: GPU / CUDA version
+      description: Leave blank if not applicable.
+      placeholder: "e.g. RTX 4090, CUDA 12.4"
+    validations:
+      required: false
+
+  - type: textarea
+    id: repro
+    attributes:
+      label: Minimal code to reproduce
+      description: A minimal script or command that reproduces the issue.
+      render: python
+    validations:
+      required: true
+
+  - type: textarea
+    id: error
+    attributes:
+      label: Error messages and stack trace
+      render: shell
+    validations:
+      required: false
+
+  - type: textarea
+    id: expected
+    attributes:
+      label: Expected vs actual behavior
+    validations:
+      required: true

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,5 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Questions and ideas
+    url: https://github.com/Project-MONAI/physiotwin4d/discussions
+    about: For "how do I..." questions, open-ended ideas, and show-and-tell — not for bugs or confirmed feature work.

.github/ISSUE_TEMPLATE/docs_issue.yml

@@ -0,0 +1,27 @@
+name: Documentation issue
+description: Something in the docs, tutorials, or docstrings is wrong, unclear, or missing.
+labels: ["documentation"]
+body:
+  - type: input
+    id: location
+    attributes:
+      label: Page or file
+      description: Link to the hosted doc page, or the source path (e.g. docs/tutorials.rst, tutorials/tutorial_09_*.py docstring).
+      placeholder: "https://project-monai.github.io/physiotwin4d/... or docs/..."
+    validations:
+      required: true
+
+  - type: textarea
+    id: problem
+    attributes:
+      label: What's wrong or missing
+    validations:
+      required: true
+
+  - type: textarea
+    id: suggestion
+    attributes:
+      label: Suggested fix
+      description: Optional — a proposed rewrite, or what you expected to find instead.
+    validations:
+      required: false

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -0,0 +1,46 @@
+name: Feature request
+description: Suggest a new capability, workflow, or extension.
+labels: ["enhancement"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        See the
+        [Feature Requests](https://project-monai.github.io/physiotwin4d/contributing.html#feature-requests)
+        section of the contributing guide for what makes a good request.
+        For open-ended ideas you're not sure are worth a formal request yet,
+        consider starting a
+        [Discussion](https://github.com/Project-MONAI/physiotwin4d/discussions)
+        instead.
+
+  - type: textarea
+    id: description
+    attributes:
+      label: Clear description
+      description: What should PhysioTwin4D do that it doesn't today?
+    validations:
+      required: true
+
+  - type: textarea
+    id: use-case
+    attributes:
+      label: Use case and motivation
+      description: What problem does this solve, and for whom?
+    validations:
+      required: true
+
+  - type: textarea
+    id: proposed-api
+    attributes:
+      label: Proposed API or interface
+      description: Sketch the workflow class, CLI flag, or signature you have in mind, if any.
+      render: python
+    validations:
+      required: false
+
+  - type: textarea
+    id: alternatives
+    attributes:
+      label: Potential challenges or alternatives considered
+    validations:
+      required: false