Initial implementation of the reconciliation script

Standalone Ruby script reconciling GoCardless payments, Dolibarr
invoices (via API), and Shine bank statements. Three-pass engine:
GC↔Dolibarr matching, open invoice audit, payout↔bank verification.
Includes dry-run and --fix mode to auto-mark Dolibarr invoices as paid.

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

lib/reconciliation/fixer.rb

@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+
+module Reconciliation
+  # Applies fixes to Dolibarr: marks invoices as paid using GoCardless payment data.
+  class Fixer
+    def initialize(client)
+      @client = client
+    end
+
+    # Accepts an array of Engine::Match objects with flag GC_PAID_DOLIBARR_OPEN
+    def apply(matches)
+      return if matches.empty?
+
+      gc_payment_id = ENV.fetch("DOLIBARR_GC_PAYMENT_ID", nil)&.to_i
+      bank_id       = ENV.fetch("DOLIBARR_BANK_ACCOUNT_ID", "1").to_i
+
+      if gc_payment_id.nil?
+        warn "[Fixer] DOLIBARR_GC_PAYMENT_ID not set in .env — cannot fix. " \
+             "Run: GET /setup/dictionary/payment_types to find the GoCardless payment type ID."
+        return
+      end
+
+      puts ""
+      puts "APPLYING FIXES (#{matches.size} invoices)..."
+
+      matches.each do |m|
+        inv = m.invoice
+        pay = m.payment
+
+        payload = {
+          arrayofamounts: {
+            inv.id.to_s => {
+              amount:                "%.2f" % (inv.amount_cents / 100.0),
+              multicurrency_amount: nil
+            }
+          },
+          datepaye:          pay.charge_date.to_time.to_i,
+          paymentid:         gc_payment_id,
+          closepaidinvoices: "yes",
+          accountid:         bank_id,
+          num_payment:       pay.id,
+          comment:           "GoCardless payment — auto-reconciled (#{pay.charge_date})"
+        }
+
+        begin
+          @client.post("/invoices/paymentsdistributed", payload)
+          puts "  ✓ Marked #{inv.ref} as paid (GC: #{pay.id})"
+        rescue Dolibarr::Client::ValidationError => e
+          puts "  ✗ #{inv.ref} — validation error: #{e.message}"
+        rescue Dolibarr::Client::Error => e
+          puts "  ✗ #{inv.ref} — API error: #{e.message}"
+        end
+      end
+    end
+  end
+end