fix(assistant): keep focus in the card, scope errors, guard links

From review of the canvas. Escape stopped working in three ways, each
leaving the keyboard grabbed with nothing to receive it: the history
field hiding took focus with it, a disabled input could not hold focus
while the daemon was down, and a click in a streaming reply focused text
the next flush destroyed. The card now gives focus back to the input
whenever it falls out, and the input is read-only rather than disabled.

Only an error the daemon marks as ending the reply (turn) closes the live
row; a command error, possibly another client's, used to freeze the reply
mid-stream. The running tool comes from state events, hello included.
Scrolling up during a stream no longer snaps back, since following stops
when a movement starts. History snippets go through Notify.sanitize like
any model output, links open only for http, https and mailto, and a line
opening with inline triple-backtick code is no longer taken as a fence.

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

1 files changed, 6 insertions, 2 deletions

diff --git a/desktop/assistant/Segments.qml b/desktop/assistant/Segments.qml
index 2b68b64..cd216df 100644
--- a/desktop/assistant/Segments.qml
+++ b/desktop/assistant/Segments.qml
@@ -45,7 +45,9 @@ Column {
                 color: Theme.text
                 selectionColor: Qt.alpha(Theme.accent, 0.4)
                 font { family: Theme.fontFamily; pixelSize: Theme.fontSize - 2 }
-                onLinkActivated: link => Qt.openUrlExternally(link)
+                // Web and mail links only: a model-written file: or custom
+                // scheme link would be handed to xdg-open.
+                onLinkActivated: link => { if (/^(https?|mailto):/i.test(link)) Qt.openUrlExternally(link); }
                 HoverHandler { cursorShape: prose.hoveredLink ? Qt.PointingHandCursor : Qt.IBeamCursor }
             }
 
@@ -77,7 +79,9 @@ Column {
                     anchors { right: parent.right; top: parent.top; margins: 6 }
                     visible: !part.modelData.open
                     width: visible ? implicitWidth : 0
-                    text: copied.running ? "Copied" : (part.modelData.lang || "Copy")
+                    text: copied.running ? "Copied" : "Copy"
+                    // ponytail: one argv string, so a block over 128 KiB
+                    // (MAX_ARG_STRLEN) fails to copy; stdin if that matters.
                     onClicked: {
                         Quickshell.execDetached(["wl-copy", "--", part.modelData.text]);
                         copied.restart();