feat(ai-tools): drop OpenCode and Grok Build

- opencode.json / grok.json leave the built-in catalog; opencode-usage.js,
  its poller, transcript branch and table creation go with it (existing
  tables and session rows stay as history).
- A Grok payload reaching the Claude hook route (Grok runs the Claude hooks
  itself) is dropped instead of recorded as tool = 'grok'.
- quota.js no longer reads Grok or OpenCode Go logins.
- Redone on v2.8.22 from c6b2892 (feat/grok-usage, never merged).

client/src/components/settings/__tests__/AiToolsSettings.test.tsx

@@ -65,7 +65,7 @@ const VIEW: AiToolsView = {
   tools: [
     tool("claude", "Claude Code"),
     tool("gemini", "Gemini"),
-    tool("grok", "Grok", { enabled: false }),
+    tool("goose", "Goose", { enabled: false }),
     tool("aider", "Aider", { installed: false, path: null }),
   ],
 };
@@ -155,9 +155,9 @@ describe("AiToolsSettings", () => {
     await user.click(within(gemini).getByText("Set default"));
     expect(api.aiTools.update).toHaveBeenCalledWith("gemini", { default: true });
     // A disabled tool cannot become the default.
-    const grok = screen.getByTestId("ai-tool-grok");
-    expect(within(grok).getByText("Set default")).toBeDisabled();
-    expect(within(grok).getByRole("switch")).toHaveAttribute("aria-checked", "false");
+    const goose = screen.getByTestId("ai-tool-goose");
+    expect(within(goose).getByText("Set default")).toBeDisabled();
+    expect(within(goose).getByRole("switch")).toHaveAttribute("aria-checked", "false");
   });
 
   it("refreshes detection", async () => {
@@ -179,7 +179,7 @@ describe("AiToolsSettings", () => {
     await user.click(screen.getByRole("menuitem", { name: "Disable" }));
     expect(api.aiTools.update).toHaveBeenCalledWith("gemini", { enabled: false });
     // A disabled tool cannot become the default from the menu either.
-    await user.pointer({ keys: "[MouseRight]", target: screen.getByTestId("ai-tool-grok") });
+    await user.pointer({ keys: "[MouseRight]", target: screen.getByTestId("ai-tool-goose") });
     expect(screen.getByRole("menuitem", { name: "Set default" })).toBeDisabled();
   });
 });
@@ -301,11 +301,9 @@ describe("AiToolsSettings — install and update", () => {
 describe("AiToolIcon", () => {
   it("retries the icon when the same instance shows another tool", async () => {
     const { AiToolIcon } = await import("../../AiToolIcon");
-    const { container, rerender } = render(
-      <AiToolIcon tool={{ id: "opencode", label: "OpenCode" }} />
-    );
+    const { container, rerender } = render(<AiToolIcon tool={{ id: "aider", label: "Aider" }} />);
     fireEvent.error(container.querySelector("img")!);
-    expect(screen.getByText("O")).toBeInTheDocument();
+    expect(screen.getByText("A")).toBeInTheDocument();
     rerender(<AiToolIcon tool={{ id: "cursor", label: "Cursor CLI" }} />);
     expect(container.querySelector('img[src="/api/ai-tools/cursor/icon"]')).toBeTruthy();
   });