feat(db): statically compile spellfix1 SQLite extension

Vendor the spellfix1 extension source and compile it directly into the
binary via cgo, avoiding runtime shared library dependencies across
platforms. The extension is registered via sqlite3_auto_extension so
every new SQLite connection has spellfix1 available.

Signed-off-by: Deluan <deluan@navidrome.org>

.github/workflows/pipeline.yml

@@ -117,7 +117,7 @@ jobs:
       - name: Test
         run: |
           pkg-config --define-prefix --cflags --libs taglib # for debugging
-          go test -shuffle=on -tags netgo,sqlite_fts5 -race ./... -v
+          go test -shuffle=on -tags netgo,sqlite_fts5,sqlite_spellfix -race ./... -v
 
       - name: Test ndpgen
         run: |