containers: Docker (and best-effort Podman) plugin

- minimal Docker Engine API client over Unix/TCP sockets with version
  negotiation and chunked response decoding
- drop-in stats schema: active/stopped containers, CPU/memory/IO/network
  rates, ports, uptime (pretty_date), image, engine field
- Docker + Podman engines, config (all, podman_sock, max_name_size,
  disable_stats, show/hide, per-container thresholds)
- export strips the computation sub-dicts (--stdout/--stdout-csv)
- TUI block above the process count
- CI-safe fake Docker socket test + live differential parity

crates/glances-tui/src/lib.rs

@@ -389,6 +389,32 @@ impl Tui {
         }
         let mut y = area.y;
 
+        // Containers (above the process count, like the Python right sidebar).
+        if let Some(plugin) = engine.plugins.get_mut("containers")
+            && plugin.is_enabled()
+        {
+            let ctx = render_ctx(args, &engine.runtime, right_width as usize);
+            let lines = split_lines(plugin.render(&ctx));
+            if !lines.is_empty() {
+                let max_height = (area.y + area.height).saturating_sub(y).saturating_sub(4);
+                let height = (lines.len() as u16).min(max_height);
+                if height > 0 {
+                    draw_lines(
+                        frame,
+                        Rect {
+                            x: right_x,
+                            y,
+                            width: right_width,
+                            height,
+                        },
+                        &lines,
+                        args,
+                    );
+                    y += height;
+                }
+            }
+        }
+
         // Process count.
         if let Some(plugin) = engine.plugins.get_mut("processcount")
             && plugin.is_enabled()
@@ -916,7 +942,7 @@ mod tests {
             "--disable-plugin",
             "all",
             "--enable-plugin",
-            "cpu,mem,load,processlist,processcount,network,fs,diskio,now,system,uptime,quicklook",
+            "cpu,mem,load,processlist,processcount,containers,network,fs,diskio,now,system,uptime,quicklook",
         ]);
         args.time = Some(1.0);
         let config = Config::empty(false);