chore(release): 0.3.0

Consolidate the Unreleased changelog into a 0.3.0 section and bump
package.json to 0.3.0. Integrates the full megalist work: completion
evidence gate + optional auditor + visible audit messages, lifecycle
ledger with reconstruction and fail-closed terminal persistence,
multi-goal management + sisyphus ordered sequences, richer goal schema,
no-tool-call + user-intervention guardrails, project-local state with
migration, agent-facing tools, deterministic compaction summary, and npm
Trusted Publishing CI.