Daily use: attachments, edit and regenerate, the chat's menu, model avatars, a palette

- Attachments from the file dialog, a drop on the window (Rust holds the dropped paths; the page
  never names one) or a paste (the bytes as the raw body of the call), sent at once to
  /api/v2/attachments as multipart and shown above the composer.
- Edit message (rewind), Regenerate reply on the last reply, Copy on both.
- The chat's menu (header and a right click in the sidebar): rename, open in the web interface,
  archive, delete.
- The chat's model and effort in its header; effort for a new chat. Model avatars coloured as
  the server's stable_hue colours them (MD5 of the id, checked against Python), mixed into the
  theme's surface so no colour is hard-coded.
- Ctrl+K palette over commands and every chat's title; Ctrl+N, Ctrl+,.
- The agent's new states in the page; 34 new sentences in all eight languages, the server's own
  words where it has them; a Czech row that was Slovak; two untranslated strings.

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

ui/js/list.js

@@ -5,7 +5,7 @@
 import { $, h, clear, when, append } from "./dom.js"
 import { get, why } from "./bridge.js"
 
-let ctx = null // { kind(), thisDevices(), open(id), current() }
+let ctx = null // { kind(), thisDevices(), open(id), current(), menu(anchor, chat) }
 let rows = []
 let more = false
 
@@ -49,6 +49,11 @@ function row(c) {
     c.device?.directory ? h("span", { class: "row__sub", title: c.device.directory }, h("bdi", { text: c.device.directory })) : null,
   )
   b.addEventListener("click", () => ctx.open(c.id))
+  // The chat's own menu (rename, archive, delete…) on a right click, or the context-menu key.
+  b.addEventListener("contextmenu", (e) => {
+    e.preventDefault()
+    ctx.menu(e.clientX || e.clientY ? { x: e.clientX, y: e.clientY } : b, c)
+  })
   return h("li", null, b)
 }