fix: exact redirects with a trailing slash or an upper-case query fire at runtime (CR-03)

The resolver fetched exact rules with lower(source) IN keys, while the keys
drop one trailing slash and keep the query as written, so a source stored
as /old/ or /list?Page=2 was never read. A new migration adds the stored
generated column source_key (the SQL form of exactKey) with an index for
exact rules, and the fetch compares it.

classes/redirects.go

@@ -117,7 +117,9 @@ func toggleSlash(p string) string {
 }
 
 // exactKey is the lookup key of an exact source: lowercased, without a
-// trailing slash on its path, with its query as written.
+// trailing slash on its path, with its query as written. The column
+// golem15_seo_redirects.source_key computes the same key in SQL (migration
+// 202610280001); change both together.
 func exactKey(source string) string {
 	p, q, hasQuery := strings.Cut(source, "?")
 	key := strings.ToLower(trimSlash(p))
@@ -225,8 +227,9 @@ func LoadRedirects(db *gorm.DB) ([]models.Redirect, error) {
 }
 
 // LoadRedirectSet reads the rule set for the resolver: every pattern and
-// regex rule now, exact rules per path as the set needs them (indexed on
-// lower(source)).
+// regex rule now, exact rules per path as the set needs them, by the
+// generated source_key column, which holds exactKey(source) (so the fetch
+// sees the same rules as an in-memory set).
 func LoadRedirectSet(db *gorm.DB) (*RedirectSet, error) {
 	var rows []models.Redirect
 	if err := db.Where("match <> ?", models.RedirectExact).Order("id ASC").Find(&rows).Error; err != nil {
@@ -235,7 +238,7 @@ func LoadRedirectSet(db *gorm.DB) (*RedirectSet, error) {
 	s := NewRedirectSet(rows)
 	s.fetch = func(keys []string) ([]models.Redirect, error) {
 		var out []models.Redirect
-		err := db.Where("match = ? AND lower(source) IN ?", models.RedirectExact, keys).Order("id ASC").Find(&out).Error
+		err := db.Where("match = ? AND source_key IN ?", models.RedirectExact, keys).Order("id ASC").Find(&out).Error
 		return out, err
 	}
 	return s, nil