fix(web): inject --bot-accent CSS variable into bot bubbles for colored accent borders

The CSS uses --bot-accent for the tinted background and left border, but the
inline style injection was missing after the remote merge. Add speakerColorDef.hex
to the two bot bubble render locations so the accent color actually applies.

apps/web/src/pages/shell/transcript.tsx

@@ -1708,6 +1708,7 @@ const MessageView = memo(function MessageView({
           <div
             data-testid="message-bot-bubble"
             className="chat-bubble-bot max-w-full space-y-3 rounded-[24px] rounded-tl-md px-5 py-3.5 text-ui-body leading-[1.62] text-foreground/95"
+            style={{ ["--bot-accent" as string]: speakerColorDef.hex }}
             dir="auto"
           >
             {visibleNarrationBlocks.map((block, i) => {
@@ -2103,6 +2104,7 @@ const MessageView = memo(function MessageView({
                 <div
                   data-testid="message-bot-bubble"
                   className="chat-bubble-bot max-w-full space-y-3 rounded-[24px] rounded-tl-md px-6 py-4 text-ui-reading leading-[1.85] text-foreground/95"
+                  style={{ ["--bot-accent" as string]: speakerColorDef.hex }}
                   dir="auto"
                 >
                   <BotTextBlockContent