fix(web): hide invalid slash skill completions

apps/web/src/components/chat/ChatComposer.tsx

@@ -146,7 +146,10 @@ import { ComposerPendingUserInputPanel } from "./ComposerPendingUserInputPanel";
 import { ComposerPlanFollowUpBanner } from "./ComposerPlanFollowUpBanner";
 import { ComposerControl, ComposerControlIcon, ComposerSelectControl } from "./ComposerControl";
 import { resolveComposerMenuActiveItemId } from "./composerMenuHighlight";
-import { searchSlashCommandItems } from "./composerSlashCommandSearch";
+import {
+  searchSlashCommandItems,
+  slashCommandItemsForPromptPosition,
+} from "./composerSlashCommandSearch";
 import {
   getComposerPromptInjectionState,
   getComposerProviderState,
@@ -1360,11 +1363,10 @@ export const ChatComposer = memo(function ChatComposer(props: ChatComposerProps)
           skill.description ??
           (skill.scope ? `${skill.scope} skill` : ""),
       }));
-      const slashCommandItems = [
-        ...builtInSlashCommandItems,
-        ...providerSlashCommandItems,
-        ...skillItems,
-      ];
+      const slashCommandItems = slashCommandItemsForPromptPosition(
+        [...builtInSlashCommandItems, ...providerSlashCommandItems, ...skillItems],
+        composerTrigger.rangeStart === 0,
+      );
       return searchSlashCommandItems(slashCommandItems, query);
     }
     if (composerTrigger.kind === "skill") {

apps/web/src/components/chat/composerSlashCommandSearch.test.ts

@@ -2,7 +2,10 @@ import { describe, expect, it } from "vite-plus/test";
 import { ProviderDriverKind } from "@t3tools/contracts";
 
 import type { ComposerCommandItem } from "./ComposerCommandMenu";
-import { searchSlashCommandItems } from "./composerSlashCommandSearch";
+import {
+  searchSlashCommandItems,
+  slashCommandItemsForPromptPosition,
+} from "./composerSlashCommandSearch";
 
 describe("searchSlashCommandItems", () => {
   const claudeDriver = ProviderDriverKind.make("claudeAgent");
@@ -173,4 +176,38 @@ describe("searchSlashCommandItems", () => {
       "skill:claudeAgent:unslop",
     ]);
   });
+
+  it("hides skills from slash completion after the first message line", () => {
+    const items = [
+      {
+        id: "slash:model",
+        type: "slash-command",
+        command: "model",
+        label: "/model",
+        description: "Switch model",
+      },
+      {
+        id: "skill:claudeAgent:unslop",
+        type: "skill",
+        provider: claudeDriver,
+        skill: {
+          name: "unslop",
+          path: "/skills/unslop/SKILL.md",
+          enabled: true,
+        },
+        label: "/skill:unslop",
+        description: "Cut AI tells from writing",
+      },
+    ] satisfies Array<
+      Extract<ComposerCommandItem, { type: "slash-command" | "provider-slash-command" | "skill" }>
+    >;
+
+    expect(slashCommandItemsForPromptPosition(items, false).map((item) => item.id)).toEqual([
+      "slash:model",
+    ]);
+    expect(slashCommandItemsForPromptPosition(items, true).map((item) => item.id)).toEqual([
+      "slash:model",
+      "skill:claudeAgent:unslop",
+    ]);
+  });
 });

apps/web/src/components/chat/composerSlashCommandSearch.ts

@@ -12,6 +12,16 @@ type SlashSearchItem = Extract<
   { type: "slash-command" | "provider-slash-command" | "skill" }
 >;
 
+export function slashCommandItemsForPromptPosition(
+  items: ReadonlyArray<SlashSearchItem>,
+  isAtPromptStart: boolean,
+): SlashSearchItem[] {
+  if (isAtPromptStart) {
+    return [...items];
+  }
+  return items.filter((item) => item.type !== "skill");
+}
+
 function scoreSlashCommandItem(item: SlashSearchItem, query: string): number | null {
   if (item.type === "skill") {
     if (query === "skill") {