docs+release: Phase 4 launch artifacts

README hero with real screenshots, install/config/widget docs, goreleaser
for dash + dash-agent, GHCR release workflow, changelog, community files,
agent systemd unit and Dockerfile, version stamping via -X main.version.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,31 @@
+name: Bug report
+description: Something is broken
+labels: [bug]
+body:
+  - type: textarea
+    id: what
+    attributes:
+      label: What happened
+      description: What you did, what you expected, what happened instead.
+    validations:
+      required: true
+  - type: textarea
+    id: logs
+    attributes:
+      label: Logs
+      description: Relevant server logs or browser console output.
+      render: text
+  - type: input
+    id: version
+    attributes:
+      label: Dash version
+      description: Image tag or release version.
+      placeholder: v0.7.0
+  - type: dropdown
+    id: install
+    attributes:
+      label: Install method
+      options:
+        - Docker
+        - Binary
+        - Built from source

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -0,0 +1,16 @@
+name: Feature request
+description: Suggest an addition
+labels: [enhancement]
+body:
+  - type: textarea
+    id: problem
+    attributes:
+      label: What problem does this solve
+      description: Concrete use case, not just "add X".
+    validations:
+      required: true
+  - type: textarea
+    id: idea
+    attributes:
+      label: Proposed shape
+      description: Optional. How it might look or work.