Docs(community): route security, conduct and support reports to the right channels

SECURITY.md used to ask for vulnerability reports in public issues while
requesting no public disclosure in the same breath; it now points at
GitHub's private advisory form, states the latest-release-only support
policy and scopes out non-code findings. The Code of Conduct's
enforcement contact — a literal blank since the file landed — now uses
the same private form. New SUPPORT.md and an issue-chooser config send
questions to Discussions Q&A and docs before they become issues, and
CONTRIBUTING drops its stale "questions also go to Issues" line.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

CONTRIBUTING.md

@@ -98,8 +98,10 @@ ships as `beta` until it's complete. Full walkthrough: **[TRANSLATING.md](TRANSL
 
 Use the issue templates in [`.github/ISSUE_TEMPLATE/`](.github/ISSUE_TEMPLATE/) —
 one for bug reports (include terminal / browser console logs) and one for feature
-requests. For general questions, GitHub Issues is also the right place; there are
-no chat channels.
+requests. Questions, setup help, and "is this a bug?" go to
+[Discussions → Q&A](https://github.com/jason5ng32/MyIP/discussions/categories/q-a)
+instead — see [SUPPORT.md](SUPPORT.md). Security vulnerabilities go through the
+private channel in [SECURITY.md](SECURITY.md), never a public issue.
 
 ## Testing