add LIKE substring fallback to search and update plan statuses

FTS5 prefix matching misses mid-word substrings (e.g. "ebook" in
"notebook"). When FTS5 returns zero results, fall back to LIKE
query on title and category with proper wildcard escaping. 4 new
tests, 757 total.

Also marks completed plan files (search, admin-redesign,
setup-wizard, products-context) with correct status.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

test/simpleshop_theme/search_test.exs

@@ -169,18 +169,24 @@ defmodule SimpleshopTheme.SearchTest do
 
   describe "index_product/1" do
     test "indexes a single product", %{ocean: ocean} do
-      # Clear and rebuild without ocean
+      # Clear FTS index
       SimpleshopTheme.Repo.query!("DELETE FROM products_search_map")
       SimpleshopTheme.Repo.query!("DELETE FROM products_search")
 
-      assert Search.search("ocean") == []
+      # Verify FTS index is empty
+      %{rows: rows} = SimpleshopTheme.Repo.query!("SELECT COUNT(*) FROM products_search_map")
+      assert rows == [[0]]
 
       # Index just ocean
       ocean = SimpleshopTheme.Repo.preload(ocean, [:variants])
       Search.index_product(ocean)
 
+      # Verify ocean is now in the FTS index
+      %{rows: [[count]]} = SimpleshopTheme.Repo.query!("SELECT COUNT(*) FROM products_search_map")
+      assert count == 1
+
       results = Search.search("ocean")
-      assert length(results) == 1
+      assert length(results) >= 1
       assert hd(results).id == ocean.id
     end
 
@@ -197,13 +203,41 @@ defmodule SimpleshopTheme.SearchTest do
     end
   end
 
+  describe "LIKE fallback" do
+    test "finds substring matches that FTS5 prefix misses", %{ocean: ocean} do
+      # "ebook" is in the middle of "Notebook" — FTS5 prefix won't match
+      results = Search.search("ebook")
+      assert Enum.any?(results, &(&1.id == ocean.id))
+    end
+
+    test "falls back to category substring match", %{forest: forest} do
+      # "ppar" is a substring of "Apparel" — FTS5 prefix won't match
+      results = Search.search("pparel")
+      assert Enum.any?(results, &(&1.id == forest.id))
+    end
+  end
+
   describe "remove_product/1" do
     test "removes a product from the index", %{ocean: ocean} do
-      assert Search.search("ocean") != []
+      # Verify ocean is in the FTS index
+      %{rows: [[rowid]]} =
+        SimpleshopTheme.Repo.query!(
+          "SELECT rowid FROM products_search_map WHERE product_id = ?1",
+          [ocean.id]
+        )
+
+      assert rowid
 
       Search.remove_product(ocean.id)
 
-      assert Search.search("ocean") == []
+      # Verify it's gone from the FTS index
+      %{rows: rows} =
+        SimpleshopTheme.Repo.query!(
+          "SELECT rowid FROM products_search_map WHERE product_id = ?1",
+          [ocean.id]
+        )
+
+      assert rows == []
     end
 
     test "is a no-op for unindexed product" do