chore(deploy): allow a gitignored local override for deploy targets

deploy.sh now sources ./.deploy.local at runtime if it exists, letting a
maintainer point the script at their own hosts without committing them — the
tracked defaults stay placeholders. .deploy.local and .deploy-local/ are
gitignored so real hostnames/IPs never land in the repo.

.gitignore

@@ -34,6 +34,12 @@ id_ed25519*
 # Generated deployment config (contains secrets)
 livekit.yaml
 
+# Local deploy targets & private ops notes — REAL hosts/IPs/users for the
+# maintainer's own infra. NEVER commit: this is a public repo. deploy.sh reads
+# .deploy.local at runtime if present; the committed defaults stay placeholders.
+/.deploy.local
+/.deploy-local/
+
 # Raw screenshot originals — optimized WebP copies live in docs/screenshots/
 demo-pictures/