Chat tabs, chat mode, own modes, compaction notice, CLI binaries again

- Terminals and file managers as tabs of a chat; chat terminals keep running on
  the server (no idle timeout) and re-attach from any device
- "Just chat" in New session and a built-in chat mode with a lean prompt and only
  web tools; custom modes with kind (coding/conversation), read-only and tool picker
- Mode selector as a dropdown
- The chat shows running compactions (automatic: tokens and share of the limit)
  and labels summaries
- Docker image builds and serves the terminal client binaries again
- Fix: atomic session updates; background title/usage writes no longer undo each
  other (auto compaction triggered one turn late)

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

core/src/provider/openai.rs

@@ -40,7 +40,7 @@ pub fn to_wire_messages(system: &str, messages: &[Message]) -> Vec<Value> {
                         Part::Text { text } if !text.is_empty() => {
                             parts.push(json!({"type": "text", "text": text}))
                         }
-                        Part::Summary { text } => parts.push(json!({
+                        Part::Summary { text, .. } => parts.push(json!({
                             "type": "text",
                             "text": format!("<conversation-summary>\n{text}\n</conversation-summary>")
                         })),