fix(common): harden CORS, sort, raw-SQL WHERE and x-custom-sql-or

Add a `hardening` config section (RESOLVESPEC_HARDENING_*) so each
fix can be switched off to restore the previous behaviour:

- cors_strict_origins: only reflect origins listed in
  cors.allowed_origins / server URLs, with credentials; `*` never
  sends credentials; fix shared-slice append of expose headers.
- sort_strict: join aliases must match `alias.identifier` (empty alias
  no longer matches everything); sort expressions reject dangerous
  functions/catalogs; cql* columns must be identifier-safe.
- sql_strict: client raw-SQL fragments must have balanced parens and
  quotes, no comments/`;`/`$$`, DML keywords, dangerous functions or
  system catalogs; a rejected fragment now fails closed ("(1=0)")
  instead of dropping the filter. Subqueries stay allowed unless
  sql_block_subqueries is set.
- x-custom-sql-or is grouped together with the client's own
  conditions (new optional WhereGrouper, implemented for bun and gorm)
  so it can no longer OR past server-side filters.

pkg/common/adapters/database/gorm.go

@@ -377,6 +377,16 @@ func (g *GormSelectQuery) WhereOr(query string, args ...interface{}) common.Sele
 	return g
 }
 
+// WhereGroup wraps the conditions added by fn in one parenthesised group ANDed with the rest.
+func (g *GormSelectQuery) WhereGroup(fn func(common.SelectQuery) common.SelectQuery) common.SelectQuery {
+	inner := *g
+	inner.db = g.db.Session(&gorm.Session{NewDB: true})
+	if res, ok := fn(&inner).(*GormSelectQuery); ok {
+		g.db = g.db.Where(res.db)
+	}
+	return g
+}
+
 func (g *GormSelectQuery) Join(query string, args ...interface{}) common.SelectQuery {
 	// Extract optional prefix from args
 	// If the last arg is a string that looks like a table prefix, use it