swarmexec v1.7.0 — service inspect editors: env, mounts, secrets, networks/aliases

TUI service-inspect overlay gains full read-modify-write ServiceUpdate editing,
plus quality-of-life fixes to the log view.

ui:
- env editor (`e`): staged KEY=VALUE list with edit-in-place; long values
  (e.g. GITLAB_OMNIBUS_CONFIG) open in a scrollable multi-line TextArea
  (Ctrl-S save, Esc cancel).
- mounts editor (`v`): volumes and bind mounts (`volume:NAME:TGT[:ro]` /
  `bind:/host:TGT[:ro]`) with a soft bind guard warning which nodes the
  service could schedule on (host paths cannot be verified — agent has no
  host fs access).
- secrets editor (`S`): add/remove secret references (mounted at
  /run/secrets/<name>).
- networks editor (`n`): add/remove attachments with name autocomplete;
  select a network and press `A` to edit that network's DNS aliases.
- inspect NETWORKS rows are collapsible (`+ net (N dns names)`), showing the
  service/task DNS names and aliases; `y` copies the selected line (OSC52).
- Volumes tab: `A` attaches a volume to a service (reverse of the mounts editor).
- staged editors share one generic list editor: a/e/d add/edit/delete,
  `y` copy (OSC52), `u` undo, `w` apply (rolling-update confirm), Esc cancel.
- one adaptive bottom footer per view; auto-refresh pauses while an overlay
  is open.

fixes:
- log view caps its TextView via SetMaxLines so it stays responsive over long
  sessions (follow toggling no longer gets starved).

No agent or wire-contract changes since v1.6.1.