shared group provisioning, upload context menu, go path fix

- provision linux users with pastilhas:officerdev ownership so server
  can always read/write, terminal users get group access
- add officerdev shared group setup to setup.sh
- move go install to ~/.local/go with GOPATH at ~/.local/go-path
- add upload file/folder items to file browser context menu

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

scripts/setup.sh

@@ -45,6 +45,24 @@ echo "════════════════════════
 echo "  Officer — dependency setup ($PM)"
 echo "═══════════════════════════════════════════"
 
+# ─── 0. shared group ──────────────────────────────────────────────────────────
+echo ""
+echo "── Shared group (officerdev) ──"
+
+if getent group officerdev &>/dev/null; then
+  skip "officerdev group"
+else
+  sudo groupadd officerdev
+  ok "created officerdev group"
+fi
+
+if id -nG "$USER" | grep -qw officerdev; then
+  skip "$USER in officerdev group"
+else
+  sudo usermod -aG officerdev "$USER"
+  ok "added $USER to officerdev group"
+fi
+
 # ─── 1. core system packages ───────────────────────────────────────────────────
 echo ""
 echo "── Core system packages ──"