fix: during workspace bulk start/stop, skip workspaces already in target state (#27108)

Previously, bulk start required every selected workspace to be stopped,
and bulk stop required every selected workspace to be running. Mixed
selections disabled both buttons entirely.

- Change the disabled checks on bulk start/stop from `every()` to
`some()` so the buttons are enabled when at least one workspace is
eligible.
- Filter workspaces by status in the mutation functions so only eligible
workspaces are sent to the API, matching the pattern used by other batch
mutations (update, favorite, unfavorite).
- Update docs to reflect the new behavior.

> [!NOTE]
> Generated by Coder Agents. [View session](https://coder.com/).

<details>
<summary>Implementation plan</summary>

## Problem

When an admin selects multiple workspaces and opens the "Bulk actions"
dropdown, the **Start** menu item is disabled unless *every* selected
workspace has `latest_build.status === "stopped"`. If even one workspace
is already running (or in any other non-stopped state), the Start button
is grayed out and unusable. Same issue applies to **Stop**.

## Changes

### 1. Relax disabled condition (`WorkspacesPageView.tsx`)

Changed `every()` to `some()` for both Start and Stop dropdown items.
The buttons are now enabled when at least one selected workspace is in
the target state.

### 2. Filter in mutations (`batchActions.ts`)

Added `.filter()` before `.map()` in both `startAllMutation` and
`stopAllMutation` so only eligible workspaces hit the API. This matches
the existing pattern in `updateAllMutation`, `favoriteAllMutation`, and
`unfavoriteAllMutation`.

### 3. Update documentation (`docs/user-guides/workspace-management.md`)

Replaced "can only be applied to a set of workspaces which are all in
the same state" with "apply to eligible workspaces in the selection,
skipping workspaces that are already in the target state."

## Testing

Four new Storybook stories:

| Story | What it tests |
|-------|---------------|
| `StartIgnoresAlreadyRunningWorkspaces` | Mixed selection; only stopped
workspaces get `startWorkspace` calls |
| `StopIgnoresAlreadyStoppedWorkspaces` | Mixed selection; only running
workspaces get `stopWorkspace` calls |
| `StartDisabledWhenNoWorkspacesAreStartable` | All running; Start
button is disabled |
| `StopDisabledWhenNoWorkspacesAreStoppable` | All stopped; Stop button
is disabled |

</details>

docs/user-guides/workspace-management.md

@@ -107,8 +107,10 @@ Admins may apply bulk operations (update, delete, start, stop) in the
 checkboxes on the left, then use the top-right **Actions** dropdown to apply the
 operation.
 
-The start and stop operations can only be applied to a set of workspaces which
-are all in the same state. For update and delete, the user will be prompted for
+The start and stop operations can be applied even when the selected workspaces
+are not all in the same state. Bulk start will only apply to selected workspaces
+that are currently stopped, and bulk stop will only apply to selected workspaces
+that are currently running. For update and delete, the user will be prompted for
 confirmation before any action is taken.
 
 ![Bulk workspace actions](../images/user-guides/workspace-bulk-actions.png)

site/src/pages/WorkspacesPage/WorkspacesPage.stories.tsx

@@ -462,6 +462,12 @@ const stoppedWorkspaces: Workspace[] = [
 	{ ...MockStoppedWorkspace, id: "3" },
 ];
 
+const mixedStateWorkspaces: Workspace[] = [
+	{ ...MockStoppedWorkspace, id: "1" },
+	{ ...MockWorkspace, id: "2" },
+	{ ...MockStoppedWorkspace, id: "3" },
+];
+
 export const StartsOnlySelectedWorkspaces: Story = {
 	beforeEach: () => {
 		spyOn(API, "getWorkspaces").mockResolvedValue({
@@ -491,6 +497,103 @@ export const StartsOnlySelectedWorkspaces: Story = {
 	},
 };
 
+export const StartIgnoresAlreadyRunningWorkspaces: Story = {
+	beforeEach: () => {
+		spyOn(API, "getWorkspaces").mockResolvedValue({
+			workspaces: mixedStateWorkspaces,
+			count: mixedStateWorkspaces.length,
+		});
+		spyOn(API, "startWorkspace").mockResolvedValue(MockWorkspaceBuild);
+	},
+	play: async ({ canvasElement }) => {
+		const canvas = within(canvasElement);
+		const body = within(document.body);
+		const user = userEvent.setup();
+
+		await selectWorkspaces(canvas, user, ["1", "2", "3"]);
+		await openBulkActions(canvas, user);
+
+		const startItem = await body.findByRole("menuitem", { name: /start/i });
+		expect(startItem).not.toHaveAttribute("data-disabled");
+		await user.click(startItem);
+
+		await waitFor(() => expect(API.startWorkspace).toHaveBeenCalledTimes(2));
+		expect(API.startWorkspace).toHaveBeenCalledWith(
+			"1",
+			MockStoppedWorkspace.latest_build.template_version_id,
+		);
+		expect(API.startWorkspace).toHaveBeenCalledWith(
+			"3",
+			MockStoppedWorkspace.latest_build.template_version_id,
+		);
+	},
+};
+
+export const StopIgnoresAlreadyStoppedWorkspaces: Story = {
+	beforeEach: () => {
+		spyOn(API, "getWorkspaces").mockResolvedValue({
+			workspaces: mixedStateWorkspaces,
+			count: mixedStateWorkspaces.length,
+		});
+		spyOn(API, "stopWorkspace").mockResolvedValue(MockWorkspaceBuild);
+	},
+	play: async ({ canvasElement }) => {
+		const canvas = within(canvasElement);
+		const body = within(document.body);
+		const user = userEvent.setup();
+
+		await selectWorkspaces(canvas, user, ["1", "2", "3"]);
+		await openBulkActions(canvas, user);
+
+		const stopItem = await body.findByRole("menuitem", { name: /stop/i });
+		expect(stopItem).not.toHaveAttribute("data-disabled");
+		await user.click(stopItem);
+
+		await waitFor(() => expect(API.stopWorkspace).toHaveBeenCalledTimes(1));
+		expect(API.stopWorkspace).toHaveBeenCalledWith("2");
+	},
+};
+
+export const StartDisabledWhenNoWorkspacesAreStartable: Story = {
+	beforeEach: () => {
+		spyOn(API, "getWorkspaces").mockResolvedValue({
+			workspaces: runningWorkspaces,
+			count: runningWorkspaces.length,
+		});
+	},
+	play: async ({ canvasElement }) => {
+		const canvas = within(canvasElement);
+		const body = within(document.body);
+		const user = userEvent.setup();
+
+		await selectWorkspaces(canvas, user, ["1", "2", "3"]);
+		await openBulkActions(canvas, user);
+
+		const startItem = await body.findByRole("menuitem", { name: /start/i });
+		expect(startItem).toHaveAttribute("data-disabled");
+	},
+};
+
+export const StopDisabledWhenNoWorkspacesAreStoppable: Story = {
+	beforeEach: () => {
+		spyOn(API, "getWorkspaces").mockResolvedValue({
+			workspaces: stoppedWorkspaces,
+			count: stoppedWorkspaces.length,
+		});
+	},
+	play: async ({ canvasElement }) => {
+		const canvas = within(canvasElement);
+		const body = within(document.body);
+		const user = userEvent.setup();
+
+		await selectWorkspaces(canvas, user, ["1", "2", "3"]);
+		await openBulkActions(canvas, user);
+
+		const stopItem = await body.findByRole("menuitem", { name: /stop/i });
+		expect(stopItem).toHaveAttribute("data-disabled");
+	},
+};
+
 const appHealthStatuses: [WorkspaceAppHealth, boolean][] = [
 	["healthy", true],
 	["disabled", true],

site/src/pages/WorkspacesPage/WorkspacesPageView.tsx

@@ -145,7 +145,7 @@ export const WorkspacesPageView: FC<WorkspacesPageViewProps> = ({
 							<DropdownMenuContent align="end">
 								<DropdownMenuItem
 									disabled={
-										!checkedWorkspaces?.every(
+										!checkedWorkspaces?.some(
 											(w) =>
 												w.latest_build.status === "stopped" &&
 												!mustUpdateWorkspace(w, canChangeVersions),
@@ -157,7 +157,7 @@ export const WorkspacesPageView: FC<WorkspacesPageViewProps> = ({
 								</DropdownMenuItem>
 								<DropdownMenuItem
 									disabled={
-										!checkedWorkspaces?.every(
+										!checkedWorkspaces?.some(
 											(w) => w.latest_build.status === "running",
 										)
 									}

site/src/pages/WorkspacesPage/batchActions.ts

@@ -33,9 +33,11 @@ export function useBatchActions(
 	const startAllMutation = useMutation({
 		mutationFn: (workspaces: readonly Workspace[]) => {
 			return Promise.all(
-				workspaces.map((w) =>
-					API.startWorkspace(w.id, w.latest_build.template_version_id),
-				),
+				workspaces
+					.filter((w) => w.latest_build.status === "stopped")
+					.map((w) =>
+						API.startWorkspace(w.id, w.latest_build.template_version_id),
+					),
 			);
 		},
 		onSuccess,
@@ -48,7 +50,11 @@ export function useBatchActions(
 
 	const stopAllMutation = useMutation({
 		mutationFn: (workspaces: readonly Workspace[]) => {
-			return Promise.all(workspaces.map((w) => API.stopWorkspace(w.id)));
+			return Promise.all(
+				workspaces
+					.filter((w) => w.latest_build.status === "running")
+					.map((w) => API.stopWorkspace(w.id)),
+			);
 		},
 		onSuccess,
 		onError: (error) => {