feat(ldap): opt-in skip TLS verification for ldaps (internal CA)

Add a per-tenant "Skip TLS certificate verification" toggle to the LDAP
admin page so admins can connect to an AD whose ldaps:// certificate is
signed by an internal/self-signed CA (Node error: "unable to verify the
first certificate"). When enabled, ldapts is given
tlsOptions.rejectUnauthorized=false; the flag is ignored for plain ldap://
(no TLS). Defaults to full verification.

New Boolean column LdapConfig.tlsRejectUnauthorized (@default(true)) +
migration; wired through DTOs, config service, all Client creations
(test/groups/user-search/import/sync) and the test-connection endpoint. UI
checkbox with an insecure-network warning (de/en). 3 new service specs;
API 218 green, web 131 green, both apps tsc clean.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/api/prisma/migrations/20260722180000_ldap_tls_reject_unauthorized/migration.sql

@@ -0,0 +1,2 @@
+-- Add opt-in TLS verification skip for ldaps:// (internal/private CA AD certs).
+ALTER TABLE "LdapConfig" ADD COLUMN IF NOT EXISTS "tlsRejectUnauthorized" BOOLEAN NOT NULL DEFAULT true;