Add frontend autoformatting and set CI to require formatted code for all languages (#6052)

# Description of Changes
Changes the strategy for autoformatting to reject PRs if they are not
formatted correctly instead of allowing them to merge and then spawning
a new PR to fix the formatting. The old strategy just caused more work
for us because we'd have to manually approve the followup PR and get it
merged, which required 2 reviewers so in practice it rarely got done and
just meant everyone's PRs ended up containing reformatting for unrelated
files, which makes code review unnecessarily difficult. If the PR's code
is not formatted correctly after this PR, a comment will be added
automatically to tell the author how to run the formatter script to fix
their code so it can go in.

This also enables autoformatting for the frontend code, using Prettier.
I've enabled it for pretty much everything in the frontend folder, other
than 3rd party files and files it doesn't make sense for. I also
excluded Markdown because it sounds likely to be more annoying to have
to autoformat the Markdown in the frontend folder but nowhere else. Open
to changing this though if people disagree.

> [!note]
> 
> Advice to reviewers: The first commit contains all of the actual logic
I've introduced (CI changes, Prettier config, etc.)
> The second commit is just the reformatting of the entire frontend
folder.
> The first commit needs proper review, the second one just give it a
spot-check that it's doing what you'd expect.

frontend/src/proprietary/components/shared/stripeCheckout/hooks/useCheckoutSession.ts

@@ -1,7 +1,7 @@
-import { useCallback } from 'react';
-import licenseService, { PlanTier } from '@app/services/licenseService';
-import { resyncExistingLicense } from '@app/utils/licenseCheckoutUtils';
-import { CheckoutState, PollingStatus } from '@app/components/shared/stripeCheckout/types/checkout';
+import { useCallback } from "react";
+import licenseService, { PlanTier } from "@app/services/licenseService";
+import { resyncExistingLicense } from "@app/utils/licenseCheckoutUtils";
+import { CheckoutState, PollingStatus } from "@app/components/shared/stripeCheckout/types/checkout";
 
 /**
  * Checkout session creation and payment handling hook
@@ -19,20 +19,20 @@ export const useCheckoutSession = (
   pollForLicenseKey: (installId: string) => Promise<void>,
   onSuccess?: (sessionId: string) => void,
   onError?: (error: string) => void,
-  onLicenseActivated?: (licenseInfo: {licenseType: string; enabled: boolean; maxUsers: number; hasKey: boolean}) => void
+  onLicenseActivated?: (licenseInfo: { licenseType: string; enabled: boolean; maxUsers: number; hasKey: boolean }) => void,
 ) => {
   const createCheckoutSession = useCallback(async () => {
     if (!selectedPlan) {
       setState({
-        currentStage: 'error',
-        error: 'Selected plan period is not available',
+        currentStage: "error",
+        error: "Selected plan period is not available",
         loading: false,
       });
       return;
     }
 
     try {
-      setState(prev => ({ ...prev, loading: true }));
+      setState((prev) => ({ ...prev, loading: true }));
 
       // Fetch installation ID from backend
       let fetchedInstallationId = installationId;
@@ -46,13 +46,13 @@ export const useCheckoutSession = (
       let existingLicenseKey: string | undefined;
       try {
         const licenseInfo = await licenseService.getLicenseInfo();
-        if (licenseInfo?.licenseType && licenseInfo.licenseType !== 'NORMAL' && licenseInfo.licenseKey) {
+        if (licenseInfo?.licenseType && licenseInfo.licenseType !== "NORMAL" && licenseInfo.licenseKey) {
           existingLicenseKey = licenseInfo.licenseKey;
           setCurrentLicenseKey(existingLicenseKey);
-          console.log('Found existing valid license for upgrade');
+          console.log("Found existing valid license for upgrade");
         }
       } catch (error) {
-        console.warn('Could not fetch license info, proceeding as new license:', error);
+        console.warn("Could not fetch license info, proceeding as new license:", error);
       }
 
       const response = await licenseService.createCheckoutSession({
@@ -66,49 +66,39 @@ export const useCheckoutSession = (
 
       // Check if we got a redirect URL (hosted checkout for HTTP)
       if (response.url) {
-        console.log('Redirecting to Stripe hosted checkout:', response.url);
+        console.log("Redirecting to Stripe hosted checkout:", response.url);
         // Redirect to Stripe's hosted checkout page
         window.location.href = response.url;
         return;
       }
 
       // Otherwise, use embedded checkout (HTTPS)
-      setState(prev => ({
+      setState((prev) => ({
         ...prev,
         clientSecret: response.clientSecret,
         sessionId: response.sessionId,
         loading: false,
       }));
     } catch (err) {
-      const errorMessage =
-        err instanceof Error ? err.message : 'Failed to create checkout session';
+      const errorMessage = err instanceof Error ? err.message : "Failed to create checkout session";
       setState({
-        currentStage: 'error',
+        currentStage: "error",
         error: errorMessage,
         loading: false,
       });
       onError?.(errorMessage);
     }
-  }, [
-    selectedPlan,
-    state.email,
-    installationId,
-    minimumSeats,
-    setState,
-    setInstallationId,
-    setCurrentLicenseKey,
-    onError
-  ]);
+  }, [selectedPlan, state.email, installationId, minimumSeats, setState, setInstallationId, setCurrentLicenseKey, onError]);
 
   const handlePaymentComplete = useCallback(async () => {
     // Preserve state when changing stage
-    setState(prev => ({ ...prev, currentStage: 'success' }));
+    setState((prev) => ({ ...prev, currentStage: "success" }));
 
     // Check if this is an upgrade (existing license key) or new plan
     if (currentLicenseKey) {
       // UPGRADE FLOW: Resync existing license with Keygen
-      console.log('Upgrade detected - resyncing existing license with Keygen');
-      setPollingStatus('polling');
+      console.log("Upgrade detected - resyncing existing license with Keygen");
+      setPollingStatus("polling");
 
       const activation = await resyncExistingLicense({
         isMounted: () => true, // Modal is open, no need to check
@@ -117,26 +107,26 @@ export const useCheckoutSession = (
 
       if (activation.success) {
         console.log(`License upgraded successfully: ${activation.licenseType}`);
-        setPollingStatus('ready');
+        setPollingStatus("ready");
       } else {
-        console.error('Failed to sync upgraded license:', activation.error);
-        setPollingStatus('timeout');
+        console.error("Failed to sync upgraded license:", activation.error);
+        setPollingStatus("timeout");
       }
 
       // Notify parent (don't wait - upgrade is complete)
-      onSuccess?.(state.sessionId || '');
+      onSuccess?.(state.sessionId || "");
     } else {
       // NEW PLAN FLOW: Poll for new license key
-      console.log('New subscription - polling for license key');
+      console.log("New subscription - polling for license key");
 
       if (installationId) {
         pollForLicenseKey(installationId).finally(() => {
           // Only notify parent after polling completes or times out
-          onSuccess?.(state.sessionId || '');
+          onSuccess?.(state.sessionId || "");
         });
       } else {
         // No installation ID, notify immediately
-        onSuccess?.(state.sessionId || '');
+        onSuccess?.(state.sessionId || "");
       }
     }
   }, [
@@ -147,7 +137,7 @@ export const useCheckoutSession = (
     setPollingStatus,
     pollForLicenseKey,
     onSuccess,
-    onLicenseActivated
+    onLicenseActivated,
   ]);
 
   return {