test: add a local Docker test environment for all features

testenv/ starts two real NetBox 4.7 instances (v2 and v1 token), SSH
targets on public, mgmt, and prod networks, a jump host, an IPv6-only
host, a static host, and a client with ssh, sftp, scp, tmux, zellij,
bash, zsh, and fish. A seed script fills NetBox through the REST API.

141 end-to-end checks cover cache and refresh filters, connecting,
all resolver strategies, multiple instances, shortcuts and rewrites,
SSH options and rules, static hosts, sftp/scp incl. IPv6 and jump
hosts, tunnels, local notes and NetBox comments, completion and shell
hooks, the TUI (driven through tmux), the configurator, and uninstall.

Local only: testenv/up.sh, test.sh, shell.sh, down.sh. Not part of
CI/CD.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

testenv/tests/10-notes.sh

@@ -0,0 +1,22 @@
+# Local notes and NetBox comments (v2 token on fsn, v1 token on lab).
+config <<'EOF'
+resolver:
+  strategies: [management_subnet, primary_ip]
+  management_subnets: [10.231.1.0/24]
+EOF
+check "refresh" netssh cache refresh
+host=fsn/fsn1-pve1.hoster.test
+check "set local note" netssh notes set $host "first line"
+check "append local note" netssh notes append $host "second line"
+expect_eq "show local note" "first line
+second line" netssh notes show $host
+expect_eq "note from stdin" "piped" bash -c "echo piped | netssh notes set $host && netssh notes show $host"
+
+expect_eq "read NetBox comments (v2 token)" "Proxmox node 1" netssh notes show $host --netbox
+check "append NetBox comments" netssh notes append $host --netbox "checked by netssh test"
+expect_out "NetBox has the new line" "checked by netssh test" curl -s -H "Authorization: Bearer $FSN_TOKEN" "$FSN_URL/api/dcim/devices/?name=fsn1-pve1.hoster.test"
+check "restore NetBox comments" netssh notes set $host --netbox "Proxmox node 1"
+
+check "set NetBox comments (v1 token)" netssh notes set lab/lab-db1 --netbox "lab note"
+expect_eq "read them back" "lab note" netssh notes show lab/lab-db1 --netbox
+check "clear them" netssh notes set lab/lab-db1 --netbox ""