chore: stop line-ending churn, track the enabled plugin

Obsidian writes CRLF on Windows, so git reported untouched files as
modified. That matters because `git diff HEAD` is the review surface
after a headless ingest and is useless if everything shows as changed.
`* -text` stores bytes as-is.

.gitattributes

@@ -0,0 +1,7 @@
+# Obsidian on Windows writes CRLF; git's default autocrlf then reports files as
+# modified when only line endings differ. That noise matters here: after a
+# headless ingest, `git diff HEAD` is the review surface for what the agent
+# wrote, and it is useless if every untouched file also shows as changed.
+#
+# Store bytes exactly as they are on disk, no conversion in either direction.
+* -text

.obsidian/community-plugins.json

@@ -0,0 +1,3 @@
+[
+  "webinar-dash"
+]