feat(cli): add --no-build flag to state push for state-only updates (#21374)

## Summary

Adds a `--no-build` flag to `coder state push` that updates the
Terraform state directly without triggering a workspace build.

## Use Case

This enables state-only migrations, such as migrating Kubernetes
resources from deprecated types (e.g., `kubernetes_config_map`) to
versioned types (e.g., `kubernetes_config_map_v1`):

```bash
coder state pull my-workspace > state.json
terraform init
terraform state rm -state=state.json kubernetes_config_map.example
terraform import -state=state.json kubernetes_config_map_v1.example default/example
coder state push --no-build my-workspace state.json
```

## Changes

- Add `PUT /api/v2/workspacebuilds/{id}/state` endpoint to update state
without triggering a build
- Add `UpdateWorkspaceBuildState` SDK method
- Add `--no-build`/`-n` flag to `coder state push`
- Add confirmation prompt (can be skipped with `--yes`/`-y`) since this
is a potentially dangerous operation
- Add test for `--no-build` functionality

Fixes #21336

coderd/workspacebuilds.go

@@ -882,6 +882,63 @@ func (api *API) workspaceBuildState(rw http.ResponseWriter, r *http.Request) {
 	_, _ = rw.Write(workspaceBuild.ProvisionerState)
 }
 
+// @Summary Update workspace build state
+// @ID update-workspace-build-state
+// @Security CoderSessionToken
+// @Accept json
+// @Tags Builds
+// @Param workspacebuild path string true "Workspace build ID" format(uuid)
+// @Param request body codersdk.UpdateWorkspaceBuildStateRequest true "Request body"
+// @Success 204
+// @Router /workspacebuilds/{workspacebuild}/state [put]
+func (api *API) workspaceBuildUpdateState(rw http.ResponseWriter, r *http.Request) {
+	ctx := r.Context()
+	workspaceBuild := httpmw.WorkspaceBuildParam(r)
+	workspace, err := api.Database.GetWorkspaceByID(ctx, workspaceBuild.WorkspaceID)
+	if err != nil {
+		httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
+			Message: "No workspace exists for this job.",
+		})
+		return
+	}
+	template, err := api.Database.GetTemplateByID(ctx, workspace.TemplateID)
+	if err != nil {
+		httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
+			Message: "Failed to get template",
+			Detail:  err.Error(),
+		})
+		return
+	}
+
+	// You must have update permissions on the template to update the state.
+	if !api.Authorize(r, policy.ActionUpdate, template.RBACObject()) {
+		httpapi.ResourceNotFound(rw)
+		return
+	}
+
+	var req codersdk.UpdateWorkspaceBuildStateRequest
+	if !httpapi.Read(ctx, rw, r, &req) {
+		return
+	}
+
+	// Use system context since we've already verified authorization via template permissions.
+	// nolint:gocritic // System access required for provisioner state update.
+	err = api.Database.UpdateWorkspaceBuildProvisionerStateByID(dbauthz.AsSystemRestricted(ctx), database.UpdateWorkspaceBuildProvisionerStateByIDParams{
+		ID:               workspaceBuild.ID,
+		ProvisionerState: req.State,
+		UpdatedAt:        dbtime.Now(),
+	})
+	if err != nil {
+		httpapi.Write(ctx, rw, http.StatusInternalServerError, codersdk.Response{
+			Message: "Failed to update workspace build state.",
+			Detail:  err.Error(),
+		})
+		return
+	}
+
+	rw.WriteHeader(http.StatusNoContent)
+}
+
 // @Summary Get workspace build timings by ID
 // @ID get-workspace-build-timings-by-id
 // @Security CoderSessionToken