Revert "models: remove legacy template-function-faker plugin row"

This reverts commit 6cc659e5c4.

crates/yaak-models/build.rs

@@ -1,5 +0,0 @@
-fn main() {
-    // Migrations are embedded with include_dir!, so trigger rebuilds when SQL files change.
-    println!("cargo:rerun-if-changed=migrations");
-    println!("cargo:rerun-if-changed=blob_migrations");
-}

crates/yaak-models/migrations/20260217000000_remove-legacy-faker-plugin.sql

@@ -1,3 +0,0 @@
--- Remove stale plugin rows left over from the brief period when faker shipped as bundled.
-DELETE FROM plugins
-WHERE directory LIKE '%template-function-faker';