Make isErrUserStatusError public and replace all verbose
!IsErrAccountDisabled(err) && !IsErrAccountLocked(err) checks
with the shorter IsErrUserStatusError(err) call.
syncUserGroups created its own db.NewSession() internally while being
called from AuthenticateUserInLDAP which already has an active session
with writes. In SQLite shared-cache mode this causes a lock conflict.
Pass the caller's session through instead, and add s.Commit() before
db.AssertExists calls in LDAP tests.
As discussed on Matrix, Vikunja currently prevents users from using LDAP
authentication if the server allows anonymous binds (common in local
environments like YunoHost). The application would previously trigger a
`log.Fatal` if `AuthLdapBindDN` or `AuthLdapBindPassword` were left
empty in the configuration.
#### **How this fixes the problem:**
* **Validation:** Removed the strict requirement for Bind credentials in
`InitializeLDAPConnection`.
* **Connection Logic:** Updated `ConnectAndBindToLDAPDirectory` to
attempt an `UnauthenticatedBind` from the `go-ldap` library when no
credentials are provided.
* **Safety:** If a Bind DN is provided, the behavior remains unchanged
(authenticated bind).
#### **Testing:**
* Tested manually on a **YunoHost** instance by replacing the binary.
* Confirmed that Vikunja now successfully starts and authenticates users
via the local LDAP (localhost) without requiring a service account.
* Added a basic unit test in `pkg/modules/auth/ldap/ldap_test.go` to
ensure the initialization logic doesn't crash with empty credentials.
*Note: This is my first contribution to a Go project (assisted by an LLM
for syntax). Feedback on code style is more than welcome!*
