Add detailed error messages for missing environment variables

The commit adds detailed error messages for missing environment variables across different configuration files. It updates the zod schema validations in different files, such as feature-flags.config.ts, personal-accounts-server-actions.ts, and others to provide more informative error messages when environment variables are not provided.

apps/web/config/feature-flags.config.ts

@@ -1,17 +1,43 @@
 import { z } from 'zod';
 
 const FeatureFlagsSchema = z.object({
-  enableThemeToggle: z.boolean(),
-  enableAccountDeletion: z.boolean(),
-  enableTeamDeletion: z.boolean(),
-  enableTeamAccounts: z.boolean(),
-  enableTeamCreation: z.boolean(),
-  enablePersonalAccountBilling: z.boolean(),
-  enableTeamAccountBilling: z.boolean(),
+  enableThemeToggle: z.boolean({
+    description: 'Enable theme toggle in the user interface.',
+    required_error: 'Provide the variable NEXT_PUBLIC_ENABLE_THEME_TOGGLE',
+  }),
+  enableAccountDeletion: z.boolean({
+    description: 'Enable account deletion.',
+    required_error: 'Provide the variable NEXT_PUBLIC_ENABLE_ACCOUNT_DELETION',
+  }),
+  enableTeamDeletion: z.boolean({
+    description: 'Enable team deletion.',
+    required_error: 'Provide the variable NEXT_PUBLIC_ENABLE_TEAM_DELETION',
+  }),
+  enableTeamAccounts: z.boolean({
+    description: 'Enable team accounts.',
+    required_error: 'Provide the variable NEXT_PUBLIC_ENABLE_TEAM_ACCOUNTS',
+  }),
+  enableTeamCreation: z.boolean({
+    description: 'Enable team creation.',
+    required_error: 'Provide the variable NEXT_PUBLIC_ENABLE_TEAMS_CREATION',
+  }),
+  enablePersonalAccountBilling: z.boolean({
+    description: 'Enable personal account billing.',
+    required_error:
+      'Provide the variable NEXT_PUBLIC_ENABLE_PERSONAL_ACCOUNT_BILLING',
+  }),
+  enableTeamAccountBilling: z.boolean({
+    description: 'Enable team account billing.',
+    required_error:
+      'Provide the variable NEXT_PUBLIC_ENABLE_ORGANIZATION_BILLING',
+  }),
 });
 
 const featuresFlagConfig = FeatureFlagsSchema.parse({
-  enableThemeToggle: true,
+  enableThemeToggle: getBoolean(
+    process.env.NEXT_PUBLIC_ENABLE_THEME_TOGGLE,
+    true,
+  ),
   enableAccountDeletion: getBoolean(
     process.env.NEXT_PUBLIC_ENABLE_ACCOUNT_DELETION,
     false,