CLAUDE.md: Restructure as lean index with @imports

[AntonioCS]

Summary

• Restructure CLAUDE.md from 435 lines to 67 lines (85% reduction)
• Move architecture reference to docs/architecture.md (loaded via @ import)
• Code conventions already covered by /makebind skill - remove duplication
• Fix stale content in both CLAUDE.md and SKILL.md

Changes

• CLAUDE.md: Lean index with key commands, main.mk flags summary, contributor workflow
• docs/architecture.md: NEW - core structure, module loading, loading order, complete module list, full assertion function list
• SKILL.md: Fix stale test framework reference, add missing module categories
• .gitignore: Granular docs ignoring instead of blanket docs

Stale content fixed

• tests/make_testing.mk → test_runner.mk + asserts.mk
• Missing databases/, infrastructure/ module categories added
• Assertion functions: 3 → 10 (complete list)
• Makefile.tpl.mk location corrected (templates/, not root)
• Missing core/util/git.mk added

Test plan

• No Make code changed - documentation only
• Verify @docs/architecture.md import works in fresh Claude session
• Verify /makebind skill covers all removed code convention content

Trello: https://trello.com/c/Y3cez4LU

🤖 Generated with Claude Code