Attach any file, take shares from other apps, and survive a backwards highlight

Attachments were images only. Now any file can be attached: from the file
chooser behind the "+" menu, or from Android's share sheet, which the app
is now in. An image still goes to the model as a picture; anything else is
stored under its own name (`<hex>-<name>`, cleaned by `safe_file_name`)
and the Claude driver ends the message with `Attached file: /abs/path`,
since the CLI reads files by path and a model cannot be shown a trace. The
user-message field is renamed `images` -> `attachments` on both sides,
with a serde alias reading the rows written before. A share arrives before
anyone has said which session it is for, so it is held in AppRoot with a
banner on the list until a session takes it; an open session takes it at
once. Unreadable shares are reported beside the composer, not thrown.

The tool card crashed the app when opened on a command holding a quoted
glob such as `-path '*/.git/*'`: highlights 1.1.0's shell lexer answers
`x '*/a/*'` with a span whose end is before its start, and AnnotatedString
refuses the range. Such spans are dropped; the library is the place for
the fix. The echo driver gains `/bash <command>` so a card with a given
command can be produced on the emulator.

ui-sandbox.sh's token salvage read the tokens block's close only at a line
start, ran past the compact `),],` the server writes, and copied `setups`
into the new config twice, which the server then refused.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

app/ui-sandbox.sh

@@ -148,7 +148,18 @@ salvaged=""
 if [ -f "$ROOT/config.ron" ]; then
     salvaged=$(awk '
         /^tokens: \[/ { in_tokens = 1; next }
-        in_tokens && /^\],/ { exit }
+        # The server writes the list back compactly, with the last entry
+        # and the close on one line: "    ),],". Reading the close only
+        # at a line start ran past it into `setups`, and the salvage then
+        # carried a second copy of that block into the new config.
+        in_tokens && /\],/ {
+            sub(/\],.*/, "")
+            if ($0 ~ /\),/) {
+                entry = entry $0 "\n"
+                if (entry !~ h) entries = entries entry
+            }
+            exit
+        }
         in_tokens {
             entry = entry $0 "\n"
             if ($0 ~ /\),/) {