chore: rename project to RememberStack

[fazpu]

Summary

• rename the product and Python package to RememberStack
• make remember.dev the canonical public home
• expose the remember CLI and REMEMBERSTACK_* configuration
• update packaging, container, Compose, documentation, decisions, and eval definitions

Verification

• 506 passed, 302 skipped locally
• lint-imports, Ruff, formatting, and Pyright pass
• built wheel installs and remember --version succeeds
• website typecheck and production build pass
• Compose configuration validates
• eval-banana validates all 100 checks
• Grok blocker review: no blockers

Docker runtime and real-PostgreSQL coverage are delegated to CI because the local Docker daemon is unavailable.

[github-actions]

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