fix(packs): use manifest names for built-in packs

[iuyua9]

Summary

• use each built-in pack's manifest.yaml name as the public pack id
• resolve built-in installs by manifest name while keeping the legacy source directory name as an alias
• keep the built-in README link pointing at the real package directory
• add integration coverage for listing and installing the no-memory-interaction-rules pack

Why

src/rulebook_ai/packs/no_memory_interation_rules/manifest.yaml declares the pack name as no-memory-interaction-rules, but rulebook-ai packs list currently shows the misspelled directory name and rulebook-ai packs add no-memory-interaction-rules cannot resolve it. This makes the CLI expose an implementation detail instead of the pack identity declared by the manifest.

Context checked: CONTRIBUTING.md, src/rulebook_ai/core.py, and the existing pack integration tests.

Tests

• uv run --extra dev pytest tests/integration/test_packs_list.py tests/integration/test_packs_add.py -q