web+coder: segmented per-agent slash menu (agent commands + skills) + cross-agent skill execution

Coder / menu now shows two groups: the active agent's commands first (manifest + live ACP available_commands), BooCoder skills second. SlashCommandPicker gains an opt-in groups prop (flat items path unchanged -> BooChat byte-identical, parity verified); ChatInput takes slashGroups; CoderPane builds the groups. Skills run under the selected agent: coder skill_invoke accepts a provider and, when external, injects the server-side skill body into a dispatched task instead of native inference. Also folds in the initial-chat skill fix (handleLandingSkill: create chat -> assign to pane -> invoke, same transition as a text send) that resolves the landing-page blank screen. BooChat slash menu + skill invocation unchanged.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/web/src/components/ChatInput.tsx

@@ -24,7 +24,7 @@ import { DropOverlay } from '@/components/DropOverlay';
 import { AgentPicker } from '@/components/AgentPicker';
 import { AgentCommandsHint } from '@/components/AgentCommandsHint';
 import { ContextBar } from '@/components/ContextBar';
-import { SlashCommandPicker } from '@/components/SlashCommandPicker';
+import { SlashCommandPicker, type SlashCommandGroup } from '@/components/SlashCommandPicker';
 import { isSlashCommandToken, parseSlashInput, slashQuery } from '@/lib/slash-command';
 import { api } from '@/api/client';
 import type { Message } from '@/api/types';
@@ -56,6 +56,13 @@ interface Props {
   // empty). Callers wire this to api.chats.skillInvoke. Omitting the prop
   // disables slash-command dispatch (input is sent as literal text).
   onSlashCommand?: (skillName: string, userMessage: string) => void | Promise<void>;
+  // v2.5.9: segmented slash-command DISPLAY source for the picker + hint. When
+  // provided (e.g. CoderPane passing [agent commands, skills]), these labeled
+  // groups are shown instead of the BooChat skills. Invocation routing still
+  // uses the skills lookup — names not in skills (opencode's /help etc.) fall
+  // through and are sent to the agent as literal text. Omitted → BooChat skills
+  // (flat, unchanged — parity).
+  slashGroups?: SlashCommandGroup[];
   // v1.10.4: send-to-chat reverse path. When chatId is provided, this input
   // registers in chatInputsRegistry so the terminal floating menu can list
   // it, and subscribes to sendToChat events scoped to this chatId. Receiving
@@ -71,7 +78,7 @@ interface Props {
   modelContextLimit?: number | null;
 }
 
-export function ChatInput({ disabled, projectId, agentId, onAgentChange, sessionId, webSearchEnabled, onSend, onForceSend, onSlashCommand, chatId, chatLabel, messages, modelContextLimit }: Props) {
+export function ChatInput({ disabled, projectId, agentId, onAgentChange, sessionId, webSearchEnabled, onSend, onForceSend, onSlashCommand, slashGroups, chatId, chatLabel, messages, modelContextLimit }: Props) {
   const { isMobile } = useViewport();
   const [value, setValue] = useState('');
   const [busy, setBusy] = useState(false);
@@ -100,6 +107,15 @@ export function ChatInput({ disabled, projectId, agentId, onAgentChange, session
     for (const s of skills) m.set(s.name, true);
     return m;
   }, [skills]);
+  // Flat display source for the hint (and the picker's no-groups fallback):
+  // caller-provided groups flattened, else the BooChat skills.
+  const slashItems = useMemo(
+    () =>
+      slashGroups
+        ? slashGroups.flatMap((g) => g.items)
+        : skills.map((s) => ({ name: s.name, description: s.description })),
+    [slashGroups, skills],
+  );
   const [fileIndex, setFileIndex] = useState<string[] | null>(null);
   const textareaRef = useRef<HTMLTextAreaElement | null>(null);
 
@@ -561,8 +577,8 @@ export function ChatInput({ disabled, projectId, agentId, onAgentChange, session
           ))}
         </div>
       )}
-      {skills.length > 0 && (
-        <AgentCommandsHint commands={skills.map((s) => ({ name: s.name, description: s.description }))} />
+      {slashItems.length > 0 && (
+        <AgentCommandsHint commands={slashItems} />
       )}
       {/* Batch 9 toolbar — agent picker + quick-toggle menu. v1.11.5.1
           inlines ContextBar in the same row so the bar lives next to the
@@ -661,11 +677,12 @@ export function ChatInput({ disabled, projectId, agentId, onAgentChange, session
       {slashState && (
         <SlashCommandPicker
           query={slashState.query}
-          items={skills}
+          items={slashItems}
+          groups={slashGroups}
           inputRef={textareaRef}
           onSelect={handleSlashSelect}
           onClose={() => setSlashState(null)}
-          emptyLabel="No skills available"
+          emptyLabel={slashGroups ? 'No commands available' : 'No skills available'}
         />
       )}
     </div>