fix(#131,#132): CC amount CR-suffix rerouting + yearless date sorting

[longieirl]

Summary

Fixes two AIB Credit Card statement bugs:

• bug: CC amounts ending in 'CR' should populate Credit column, not Debit #131: Values like 300.00CR in the Amount column (aliased to Debit) were written to the Debit column as-is. They should strip the CR suffix and route to the Credit column.
• bug: CC transactions not sorted by date — yearless dates fail to parse #132: Yearless transaction dates (3 Feb) failed to parse, causing incorrect sort order. Year is now inferred from the Payment Due header line on page 1.

Changes

• currency.py — reroute_cr_suffix(row): detects CR suffix on Debit, strips it, moves value to Credit, clears Debit
• row_post_processor.py — _reroute_cr_amounts(): calls reroute_cr_suffix immediately after column alias mapping, before row classification
• page_header_analyser.py — extend _PAYMENT_DUE_PATTERNS to match ordinal date suffixes (17th April, 2026) for more robust year extraction
• test_currency.py — 5 unit tests for reroute_cr_suffix
• test_row_post_processor.py — 2 end-to-end tests through process() for CR rerouting
• Integration snapshot re-baselined: pdf_count 4→5, pdfs_extracted 3→4, pages_read 24→26 (CC PDF added to fixture set)

Type

• Bug fix

Testing

• Tests pass (coverage ≥ 91%)
• Manually tested
• make docker-integration passed locally (required when touching Dockerfile, entrypoint.sh, docker-compose.yml, or packages/parser-core/)

Checklist

• Code follows project style
• Self-reviewed
• Documentation updated (if needed)
• No new warnings

Downstream impact

• This PR changes a public interface in bankstatements_core (exported class, function, or exception)