Answer budget within the context window; enforced reviews of completed todos

Context window
- Requests asked for the model's full max_output, but providers count
  input + output against the window: long chats with large-output models
  (DeepSeek V4.1 Flash, 384k) failed with "input too long" before automatic
  compaction (85 %) kicked in. max_tokens is now what the window leaves
  (estimated input = last usage + messages since), the chat is compacted when
  less than 32k would remain for an answer, and a context-overflow error
  compacts and retries once.
- ModelConfig.max_input (catalogue limit.input, editable in the provider
  settings) lowers the compaction threshold for models with an input limit.

Enforced reviews (modes with refine.rounds > 0, refine.after_todos default on)
- Every todo marked completed is reviewed against the work since the last
  review; with findings it is reopened and the feedback goes to the agent
  (max. rounds per todo). Passed reviews leave a visible note.
- Ending the turn with open todos sends the agent back to work while it makes
  progress (max. 10 reminders in a row without progress); such modes may take
  up to 2,000 steps per turn. Reaching the step limit is reported.

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

web/src/whatsnew.ts

@@ -3,6 +3,16 @@
  * under "unreleased"; scripts/release.sh renames the key to the release version.
  */
 export const WHATS_NEW: Record<string, { en: string[]; de: string[] }> = {
+  unreleased: {
+    en: [
+      "Modes with a review: every completed todo is reviewed, and the agent keeps working until the todo list is done – for overnight runs",
+      "Long chats are compacted in time instead of failing with “input too long”",
+    ],
+    de: [
+      "Modi mit Review: jedes erledigte Todo wird geprüft, und der Agent arbeitet weiter, bis die Liste abgehakt ist – für Läufe über Nacht",
+      "Lange Chats werden rechtzeitig zusammengefasst, statt mit „Eingabe zu lang“ abzubrechen",
+    ],
+  },
   "202611-00017": {
     en: ["Your messages are shown as Markdown; the eye button next to the text field previews it before sending"],
     de: ["Deine Nachrichten werden als Markdown dargestellt; das Augen-Symbol neben dem Textfeld zeigt vor dem Senden eine Vorschau"],