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, 4 insertions, 0 deletions

diff --git a/desktop/assistant/test_md.js b/desktop/assistant/test_md.js
index 030cdc9..58bf974 100644
--- a/desktop/assistant/test_md.js
+++ b/desktop/assistant/test_md.js
@@ -43,6 +43,10 @@ assert.deepStrictEqual(split("1. Install:\n   ```sh\n   make\n     make install\
                        [prose("1. Install:"), code("sh", "make\n  make install"), prose("2. Go")]);
 // A shorter or different closing run does not close the fence.
 assert.deepStrictEqual(split("````\n```\n~~~\n````"), [code("", "```\n~~~")]);
+// Inline triple-backtick code at a line start is not a fence.
+assert.deepStrictEqual(split("```x``` is inline\nmore"), [prose("```x``` is inline\nmore")]);
+// Words after the language are ignored.
+assert.deepStrictEqual(split("```python title=a\nx\n```"), [code("python", "x")]);
 // Tilde fences.
 assert.deepStrictEqual(split("~~~js\nx\n~~~"), [code("js", "x")]);
 // A closing fence with text after it is content, not a close.