Fix: Post ID ordering not working on frontend

[ryanwelcher]

Closes #148

Problem

When "Post Order By" is set to "Post ID" in the AQL block, posts display in correct order in the editor but fall back to date ordering on the frontend. Query Monitor confirms WP_Query uses ORDER BY post_date instead of ORDER BY ID.

Root Cause

• UI passes lowercase 'id' value to backend
• REST API (editor) automatically normalizes 'id' → 'ID'
• WP_Query (frontend) is case-sensitive and requires uppercase 'ID'
• Unrecognized lowercase 'id' causes fallback to default date ordering

Solution

Created OrderBy trait that normalizes the orderBy parameter:

• Accepts lowercase 'id' from block attributes
• Converts to uppercase 'ID' for WP_Query compatibility
• Ensures consistent behavior across editor and frontend

Changes

• Add includes/Traits/OrderBy.php with normalization logic
• Update Query_Params_Generator.php to use OrderBy trait
• Update query-loop.php to process orderBy parameter
• Add comprehensive e2e tests (6 tests, 100% passing)
• Add test documentation and blueprint setup
• Update CLAUDE.md with architecture notes

Testing

E2e tests verify:

• UI control displays Post ID option
• Block attributes set correctly
• Editor preview orders by ID
• Frontend orders by ID (not date)
• Ascending and descending order work
• Switching between order types works

Tests confirmed:

• ✅ 6/6 pass with fix
• ❌ 2/6 fail without fix (reproduces bug)