Address review feedback on hidden columns test

- Make setup idempotent by dropping objects before creating them
- Rename local variable proc to procedure to avoid ambiguity

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: yahonda

spec/plsql/procedure_spec.rb

@@ -2389,6 +2389,8 @@ def new_candidate(status)
 describe "Procedure with %ROWTYPE parameter on table that has hidden columns" do
   before(:all) do
     plsql.connect! CONNECTION_PARAMS
+    plsql.execute "DROP PACKAGE test_hidden_cols_pkg" rescue nil
+    plsql.execute "DROP TABLE test_hidden_cols" rescue nil
     plsql.execute "CREATE TABLE test_hidden_cols (col1 VARCHAR2(50), col2 VARCHAR2(50))"
     # Functional index creates a hidden column in ALL_TAB_COLS
     plsql.execute "CREATE INDEX test_hidden_cols_idx ON test_hidden_cols (UPPER(col1))"
@@ -2414,8 +2416,8 @@ def new_candidate(status)
   end
 
   it "should not include hidden columns in %ROWTYPE fields" do
-    proc = PLSQL::Procedure.find(plsql, :test_proc, "TEST_HIDDEN_COLS_PKG")
-    fields = proc.arguments[0][:p_rec][:fields]
+    procedure = PLSQL::Procedure.find(plsql, :test_proc, "TEST_HIDDEN_COLS_PKG")
+    fields = procedure.arguments[0][:p_rec][:fields]
     field_names = fields.keys
     expect(field_names).to include(:col1)
     expect(field_names).to include(:col2)