feat(assistant): Ask presets in the file state

A row of canned questions matching every staged file's kind, plus Compare
for two or more files: one click asks it, Shift+click puts it in the input
to edit first. Defaults live in Presets.js and the list in use in Prefs, so
a future drawer settings page can edit it; a saved list that does not
validate reads as the defaults. Each prompt asks for an answer in the
document's language. Code and configuration get their own kind, so a
script is offered Explain and Review rather than Summarize. Button's
clicked signal carries the mouse event for the Shift check.

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

1 files changed, 46 insertions, 0 deletions

diff --git a/desktop/assistant/Presets.js b/desktop/assistant/Presets.js
new file mode 100644
index 0000000..116d7d0
--- /dev/null
+++ b/desktop/assistant/Presets.js
@@ -0,0 +1,46 @@
+// Copyright (C) 2026 Danilo M. <danix@danix.xyz>
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License version 2 as
+// published by the Free Software Foundation.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+.pragma library
+
+// Canned questions for the file state's Ask row. kinds lists the staged
+// kinds a preset applies to (Files.js); ["many"] offers it whenever two or
+// more files are staged. The list in use is Prefs.presets when one is
+// saved (a settings page will edit it), these otherwise.
+const DEFAULTS = [
+    { label: "Summarize", kinds: ["pdf", "text"], prompt: "Summarize this in a few short paragraphs." },
+    { label: "Key points", kinds: ["pdf"], prompt: "List the key points as bullets." },
+    { label: "Explain simply", kinds: ["pdf", "text"], prompt: "Explain this simply, as to a non-expert." },
+    { label: "Describe", kinds: ["image"], prompt: "Describe this image." },
+    { label: "Extract text", kinds: ["image", "pdf"], prompt: "Transcribe all the text, keeping the layout where it helps." },
+    { label: "What is this?", kinds: ["image"], prompt: "What is this, and what is it for?" },
+    { label: "Explain", kinds: ["code"], prompt: "Explain what this code does." },
+    { label: "Review", kinds: ["code"], prompt: "Review this code: bugs, risks, and simplifications." },
+    { label: "Compare", kinds: ["many"], prompt: "Compare these files: what they share and how they differ." },
+];
+
+// The saved list if it is one, else the defaults: a hand edit with a typo
+// must not leave the row empty.
+function list(saved) {
+    const ok = Array.isArray(saved) && saved.every(p => p && typeof p.label === "string"
+        && typeof p.prompt === "string" && Array.isArray(p.kinds));
+    return ok ? saved : DEFAULTS;
+}
+
+function offered(presets, files) {
+    if (!files.length) return [];
+    return presets.filter(p => p.kinds.includes("many") ? files.length > 1
+                                                       : files.every(f => p.kinds.includes(f.kind)));
+}
+
+// The model answers in the language it is asked in; a preset is asked in
+// English, so it says which language to use.
+function prompt(p) { return p.prompt + " Answer in the language of the document."; }