feat(lanes,run,pricing): Changes sidebar editor, staged groups, image drop, auto pricing

- Changes panel at full screen: the whole Files view (finder, expand-all,
  tree) becomes a left sidebar and the Files tab is dropped; a working-copy
  file opens straight into the editor (Save/Cancel live once the text
  differs, Cancel restores it, Whole file toggles back to the diff), and the
  page is height-locked so the editor no longer collapses with no live run.
- Overview splits into Staged Changes / Changes groups in the work range.
- A changed file's whole tree row takes its status tint.
- Drag an image onto the lane terminal: POST /api/run/drop-image saves it
  (png/jpeg/gif/webp, random name, 0600, pruned after a day) and the path
  is pasted into the pane, which is how claude attaches it.
- Claude Opus 5.5 gets its own pricing row (4/20/0.2/5/8, fast 8/40);
  claude-opus-5% had been pricing it as Opus 5.
- server/lib/pricing-sync.js: a model family used in token_usage with no
  row of its own is inserted from LiteLLM's public price list, never
  updated; off with AGENTHUB_PRICING_SYNC=0. repo-links allows exactly
  that one third-party GitHub raw URL.

client/src/components/lanes/__tests__/LaneChangesPanel.test.tsx

@@ -11,7 +11,7 @@
  */
 
 import { describe, it, expect, vi, beforeEach } from "vitest";
-import { render, screen, waitFor, act } from "@testing-library/react";
+import { render, screen, waitFor, act, within } from "@testing-library/react";
 import userEvent from "@testing-library/user-event";
 import { LaneChangesPanel } from "../LaneChangesPanel";
 import { api } from "../../../lib/api";
@@ -80,6 +80,13 @@ function changes(over: Partial<Extract<LaneChanges, { available: true }>> = {}):
   };
 }
 
+/** The overview row's discard button for one path. */
+function discardOf(path: string) {
+  return within(screen.getByText(path).closest("li")!).getByRole("button", {
+    name: "Discard this file's changes",
+  });
+}
+
 beforeEach(() => {
   vi.mocked(api.lanes.git).mockReset().mockResolvedValue({ available: false });
   vi.mocked(api.lanes.changes).mockReset();
@@ -301,13 +308,82 @@ describe("LaneChangesPanel", () => {
     });
   });
 
+  it("lists staged files apart from the changes the next commit leaves behind", async () => {
+    render(<LaneChangesPanel laneId={7} />);
+    const list = await screen.findByTestId("lane-changes-overview");
+    const staged = list.querySelector('[data-group="staged"]') as HTMLElement;
+    const unstaged = list.querySelector('[data-group="unstaged"]') as HTMLElement;
+    expect(within(staged).getByText("docs/API.md")).toBeInTheDocument();
+    expect(within(staged).queryByText("notes.txt")).toBeNull();
+    expect(within(unstaged).getByText("server/lib/git-ops.js")).toBeInTheDocument();
+    expect(within(unstaged).getByText("notes.txt")).toBeInTheDocument();
+    expect(within(unstaged).queryByText("docs/API.md")).toBeNull();
+    expect(screen.getByText("Staged Changes")).toBeInTheDocument();
+  });
+
+  it("at full width shows the tree as a sidebar and opens a file straight into the editor", async () => {
+    vi.mocked(api.lanes.gitTree).mockResolvedValue({
+      available: true,
+      path: "",
+      entries: [{ name: "main.ts", path: "src/main.ts", dir: false, status: " M" }],
+      truncated: false,
+    });
+    vi.mocked(api.lanes.gitFile).mockResolvedValue({
+      available: true,
+      path: "src/main.ts",
+      rev: "work",
+      binary: false,
+      truncated: false,
+      lines: ["const whole = 1;"],
+      sha: "b".repeat(40),
+    });
+    const user = userEvent.setup();
+    render(<LaneChangesPanel laneId={7} full />);
+    const sidebar = await screen.findByTestId("lane-changes-sidebar");
+    // The sidebar IS the Files view: its finder lives there, and the tab is gone.
+    expect(within(sidebar).getByLabelText("Find a file by path…")).toBeInTheDocument();
+    expect(screen.queryByRole("button", { name: "Files" })).toBeNull();
+    expect(screen.getAllByTestId("lane-changes-browse")).toHaveLength(1);
+    await user.click(await within(sidebar).findByText("main.ts"));
+
+    // No Edit click: the editor is simply there, Save/Cancel idle until typed.
+    const editor = await screen.findByTestId("lane-file-editor");
+    expect(editor).toHaveValue("const whole = 1;");
+    expect(screen.queryByTestId("lane-file-edit")).toBeNull();
+    expect(screen.getByTestId("lane-file-save")).toBeDisabled();
+    await user.type(editor, "x");
+    expect(screen.getByTestId("lane-file-save")).toBeEnabled();
+    // Cancel reverts to the saved text and stays in the editor.
+    await user.click(screen.getByRole("button", { name: "Cancel" }));
+    expect(await screen.findByTestId("lane-file-editor")).toHaveValue("const whole = 1;");
+  });
+
+  it("at full width opens a changed file from the overview straight into the editor", async () => {
+    vi.mocked(api.lanes.gitFile).mockResolvedValue({
+      available: true,
+      path: "server/lib/git-ops.js",
+      rev: "work",
+      binary: false,
+      truncated: false,
+      lines: ["a"],
+      sha: "b".repeat(40),
+    });
+    const user = userEvent.setup();
+    render(<LaneChangesPanel laneId={7} full />);
+    const list = await screen.findByTestId("lane-changes-overview");
+    await user.click(within(list).getByText("server/lib/git-ops.js"));
+    expect(await screen.findByTestId("lane-file-editor")).toHaveValue("a");
+    expect(screen.queryByTestId("lane-file-edit")).toBeNull();
+    expect(screen.getByTestId("lane-file-save")).toBeDisabled();
+    expect(screen.getByRole("button", { name: "Cancel" })).toBeDisabled();
+  });
+
   it("needs two clicks to discard, and only the second one reaches the server", async () => {
     const user = userEvent.setup();
     render(<LaneChangesPanel laneId={7} />);
     await screen.findByTestId("lane-changes-overview");
 
-    const [discard] = screen.getAllByRole("button", { name: "Discard this file's changes" });
-    await user.click(discard!);
+    await user.click(discardOf("server/lib/git-ops.js"));
     expect(api.lanes.gitAction).not.toHaveBeenCalled();
 
     await user.click(
@@ -341,8 +417,7 @@ describe("LaneChangesPanel", () => {
     const user = userEvent.setup();
     render(<LaneChangesPanel laneId={7} />);
     await screen.findByTestId("lane-changes-overview");
-    const [discard] = screen.getAllByRole("button", { name: "Discard this file's changes" });
-    await user.click(discard!);
+    await user.click(discardOf("server/lib/git-ops.js"));
 
     // The file was committed/reverted elsewhere; a later reappearance must not be pre-armed.
     const base = changes();