feat: add community roadmap infrastructure

- Discussion templates for feature requests and roadmap updates
- Roadmap labels (now/next/later, community-request)
- Fix security audit report path in .gitignore

.github/DISCUSSION_TEMPLATE/roadmap-update.yml

@@ -0,0 +1,47 @@
+title: ""
+labels: []
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Periodic roadmap updates from the maintainers. See the [full roadmap board](https://github.com/orgs/snapotter-hq/projects) for current status.
+
+  - type: textarea
+    id: shipped
+    attributes:
+      label: Shipped
+      description: What landed since the last update?
+    validations:
+      required: false
+
+  - type: textarea
+    id: now
+    attributes:
+      label: Now (actively working on)
+      description: What's currently in progress?
+    validations:
+      required: true
+
+  - type: textarea
+    id: next
+    attributes:
+      label: Next (coming soon)
+      description: What's planned for the near term?
+    validations:
+      required: true
+
+  - type: textarea
+    id: later
+    attributes:
+      label: Later (on the radar)
+      description: What's being considered but not yet scheduled?
+    validations:
+      required: false
+
+  - type: textarea
+    id: community
+    attributes:
+      label: Community highlights
+      description: Shoutouts, top-voted feature requests, notable contributions.
+    validations:
+      required: false