fix: correct Sequelize alias case for OIDCIdentity-User association (#1015)

* fix: use nullish coalescing for recurrence weekday to allow Sunday selection

Fixes #812

When creating a "Monthly on weekday" recurring task, the selector would
jump back to Monday when trying to select Sunday. This was caused by using
the logical OR operator (||) instead of the nullish coalescing operator (??)
when handling the recurrence_weekday value.

Since Sunday is represented as 0, the || operator treated it as falsy and
defaulted to null/undefined, which then defaulted to 1 (Monday).

Changes:
- Replace || with ?? for recurrence_weekday in TaskRecurrenceCard.tsx
- Replace || with ?? for recurrence_weekday in TaskDetails.tsx
- Also fix recurrence_week_of_month and recurrence_month_day for consistency

* fix: correct Sequelize alias case for OIDCIdentity-User association

Fixes #1013

Changed all instances of lowercase 'user' to 'User' to match the
association defined in models/index.js. This resolves the Sequelize
error during OIDC callback:
"User is associated to OIDCIdentity using an alias. You've included
an alias (user), but it does not match the alias(es) defined in your
association (User)."

Changes:
- oidcIdentityService.js: 'user' -> 'User'
- provisioningService.js: 'user' -> 'User' (2 instances)

backend/modules/oidc/oidcIdentityService.js

@@ -22,7 +22,7 @@ async function getIdentityById(identityId) {
         include: [
             {
                 model: User,
-                as: 'user',
+                as: 'User',
                 attributes: ['id', 'email', 'username', 'is_admin'],
             },
         ],

backend/modules/oidc/provisioningService.js

@@ -22,7 +22,7 @@ async function findOrCreateIdentity(providerSlug, claims) {
             provider_slug: providerSlug,
             subject: claims.sub,
         },
-        include: [{ model: User, as: 'user' }],
+        include: [{ model: User, as: 'User' }],
     });
 
     return identity;
@@ -42,7 +42,7 @@ async function provisionUser(providerSlug, claims, req) {
                 provider_slug: providerSlug,
                 subject: claims.sub,
             },
-            include: [{ model: User, as: 'user' }],
+            include: [{ model: User, as: 'User' }],
             transaction,
         });