Add dashboard IPs/restart/connections, SMB read-only and recycle bin

Dashboard:
- Server IPs card showing all non-loopback IPv4 interfaces
- Restart buttons next to smbd/nfsd status dots (POST /api/service/<name>/restart)
- Active SMB connections table (smbstatus -b parsed in backend)

SMB edit modal:
- Read only toggle (writable vs read only in smb.conf)
- Recycle Bin toggle (vfs objects = recycle, files go to .recycle folder)

Docs: PLANNING.md phase 3.5, README recycle bin + read-only, CLAUDE.md JS overview

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

PLANNING.md

@@ -89,7 +89,20 @@ MicroNAS/
 - [x] Status indicator per share row (green/red dot, reduced opacity when
       disabled).
 
-### Phase 4 — Nice-to-have
+### Phase 3.5 — Share & dashboard polish ✅
+- [x] **Permission editor in edit modal** — owner, group, chmod mode per share
+      folder. Owner/Group are dropdowns from live system users/groups.
+- [x] **Group management** — create/delete groups, add/remove members. Users tab.
+- [x] **SMB extra settings** — force user, force group, guest ok, read only,
+      recycle bin (vfs objects = recycle, files go to .recycle inside share).
+- [x] **NFS extra settings** — no_root_squash, all_squash toggles.
+- [x] **Server IPs on dashboard** — shows all non-loopback IPv4 addresses.
+- [x] **Service restart buttons** — restart smbd / nfsd from the dashboard.
+- [x] **Active SMB connections** — live table on dashboard via smbstatus.
+- [x] **Delete confirmation modal** — replaces browser confirm().
+- [x] **Auto-refresh countdown** — 30 s timer with live seconds display.
+
+### Phase 4 — WebDAV + extras
 - [ ] **WebDAV** support. Preferred approach: drop an Apache/nginx config
       snippet — don't build it in Flask.
 - [ ] Simple in-browser file browser for `/srv`.