Data provider simplification, tests, and documentation (#1997)

* Ignore env.test from source control

* Simplification of providers interface

* Synth tests

* Update money to use new find rates method

* Remove unused issues code

* Additional issue feature removals

* Update price data fetching and tests

* Update documentation for providers

* Security test fixes

* Fix self host test

* Update synth usage data access

* Remove AI pr schema changes

db/migrate/20250315191233_remove_ticker_from_security_prices.rb

@@ -0,0 +1,5 @@
+class RemoveTickerFromSecurityPrices < ActiveRecord::Migration[7.2]
+  def change
+    remove_column :security_prices, :ticker
+  end
+end

db/migrate/20250316103753_remove_issues.rb

@@ -0,0 +1,11 @@
+class RemoveIssues < ActiveRecord::Migration[7.2]
+  def change
+    drop_table :issues do |t|
+      t.references :issuable, polymorphic: true, null: false
+      t.string :type, null: false
+      t.integer :severity, null: false
+      t.datetime :last_observed_at
+      t.datetime :resolved_at
+    end
+  end
+end

db/migrate/20250316122019_security_price_unique_index.rb

@@ -0,0 +1,31 @@
+class SecurityPriceUniqueIndex < ActiveRecord::Migration[7.2]
+  def change
+    # First, we have to delete duplicate prices from DB so we can apply the unique index
+    reversible do |dir|
+      dir.up do
+        execute <<~SQL
+          DELETE FROM security_prices
+          WHERE id IN (
+            SELECT id FROM (
+              SELECT id,
+              ROW_NUMBER() OVER (
+                PARTITION BY security_id, date, currency
+                ORDER BY updated_at DESC, id DESC
+              ) as row_num
+              FROM security_prices
+            ) as duplicates
+            WHERE row_num > 1
+          );
+        SQL
+      end
+    end
+
+    add_index :security_prices, [ :security_id, :date, :currency ], unique: true
+    change_column_null :security_prices, :date, false
+    change_column_null :security_prices, :price, false
+    change_column_null :security_prices, :currency, false
+
+    change_column_null :exchange_rates, :date, false
+    change_column_null :exchange_rates, :rate, false
+  end
+end