fix(SEC-REVIEW-1): Surface search errors in LinkAutocomplete

Previously the catch block in searchEntries silently swallowed all
non-abort errors, showing "No entries found" when the search actually
failed. This misled users into thinking the knowledge base was empty.

- Add searchError state variable
- Set PDA-friendly error message on non-abort failures
- Clear error state on subsequent successful searches
- Render error in amber (distinct from gray "No entries found")
- Add 3 tests: error display, error clearing, abort exclusion

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/web/src/components/knowledge/__tests__/LinkAutocomplete.test.tsx

@@ -207,6 +207,151 @@ describe("LinkAutocomplete", (): void => {
     vi.useRealTimers();
   });
 
+  it("should show error message when search fails", async (): Promise<void> => {
+    vi.useFakeTimers();
+
+    mockApiRequest.mockRejectedValue(new Error("Network error"));
+
+    render(<LinkAutocomplete textareaRef={textareaRef} onInsert={onInsertMock} />);
+
+    const textarea = textareaRef.current;
+    if (!textarea) throw new Error("Textarea not found");
+
+    // Simulate typing [[fail
+    act(() => {
+      textarea.value = "[[fail";
+      textarea.setSelectionRange(6, 6);
+      fireEvent.input(textarea);
+    });
+
+    // Advance past debounce to fire the search
+    await act(async () => {
+      await vi.advanceTimersByTimeAsync(300);
+    });
+
+    // Allow microtasks (promise rejection handler) to settle
+    await act(async () => {
+      await vi.advanceTimersByTimeAsync(0);
+    });
+
+    // Should show PDA-friendly error message instead of "No entries found"
+    expect(screen.getByText("Search unavailable — please try again")).toBeInTheDocument();
+
+    // Verify "No entries found" is NOT shown (error takes precedence)
+    expect(screen.queryByText("No entries found")).not.toBeInTheDocument();
+
+    vi.useRealTimers();
+  });
+
+  it("should clear error message on successful search", async (): Promise<void> => {
+    vi.useFakeTimers();
+
+    // First search fails
+    mockApiRequest.mockRejectedValueOnce(new Error("Network error"));
+
+    render(<LinkAutocomplete textareaRef={textareaRef} onInsert={onInsertMock} />);
+
+    const textarea = textareaRef.current;
+    if (!textarea) throw new Error("Textarea not found");
+
+    // Trigger failing search
+    act(() => {
+      textarea.value = "[[fail";
+      textarea.setSelectionRange(6, 6);
+      fireEvent.input(textarea);
+    });
+
+    await act(async () => {
+      await vi.advanceTimersByTimeAsync(300);
+    });
+
+    // Allow microtasks (promise rejection handler) to settle
+    await act(async () => {
+      await vi.advanceTimersByTimeAsync(0);
+    });
+
+    expect(screen.getByText("Search unavailable — please try again")).toBeInTheDocument();
+
+    // Second search succeeds
+    mockApiRequest.mockResolvedValueOnce({
+      data: [
+        {
+          id: "1",
+          slug: "test-entry",
+          title: "Test Entry",
+          summary: "A test entry",
+          workspaceId: "workspace-1",
+          content: "Content",
+          contentHtml: "<p>Content</p>",
+          status: "PUBLISHED" as const,
+          visibility: "PUBLIC" as const,
+          createdBy: "user-1",
+          updatedBy: "user-1",
+          createdAt: new Date(),
+          updatedAt: new Date(),
+          tags: [],
+        },
+      ],
+      meta: { total: 1, page: 1, limit: 10, totalPages: 1 },
+    });
+
+    // Trigger successful search
+    act(() => {
+      textarea.value = "[[success";
+      textarea.setSelectionRange(9, 9);
+      fireEvent.input(textarea);
+    });
+
+    await act(async () => {
+      await vi.advanceTimersByTimeAsync(300);
+    });
+
+    // Allow microtasks (promise resolution handler) to settle
+    await act(async () => {
+      await vi.advanceTimersByTimeAsync(0);
+    });
+
+    // Error message should be gone, results should show
+    expect(screen.queryByText("Search unavailable — please try again")).not.toBeInTheDocument();
+    expect(screen.getByText("Test Entry")).toBeInTheDocument();
+
+    vi.useRealTimers();
+  });
+
+  it("should not show error for aborted requests", async (): Promise<void> => {
+    vi.useFakeTimers();
+
+    // Make the API reject with an AbortError
+    const abortError = new DOMException("The operation was aborted.", "AbortError");
+    mockApiRequest.mockRejectedValue(abortError);
+
+    render(<LinkAutocomplete textareaRef={textareaRef} onInsert={onInsertMock} />);
+
+    const textarea = textareaRef.current;
+    if (!textarea) throw new Error("Textarea not found");
+
+    // Simulate typing [[abc
+    act(() => {
+      textarea.value = "[[abc";
+      textarea.setSelectionRange(5, 5);
+      fireEvent.input(textarea);
+    });
+
+    await act(async () => {
+      await vi.advanceTimersByTimeAsync(300);
+    });
+
+    // Should NOT show error message for aborted requests
+    // Allow a tick for the catch to process
+    await act(async () => {
+      await vi.advanceTimersByTimeAsync(0);
+    });
+
+    expect(screen.queryByText("Search unavailable — please try again")).not.toBeInTheDocument();
+
+    vi.useRealTimers();
+  });
+
   // TODO: Fix async/timer interaction - component works but test has timing issues with fake timers
   it.skip("should perform debounced search when typing query", async (): Promise<void> => {
     vi.useFakeTimers();