fix: pyproject.toml description out of sync with v1.2 positioning

[KJ-AIML]

Problem

pyproject.toml line 4 says:

Cognitive Memory Runtime for AI Agents

README and all marketing materials moved to:

Observable Memory Infrastructure for AI Agents

This inconsistency hurts search indexing and package discovery.

Fix

One-line change in pyproject.toml to match README positioning.

[KJ-AIML]

Implemented in branch fix/credibility-hardening-2026-05-27.

Changed description from "Cognitive Memory Runtime..." to "Observable Memory Infrastructure for AI Agents — hierarchical, explainable, and self-managing" to match README v1.2 positioning.

[KJ-AIML]

Fixed in PR #6.