chore(release): v0.5.0

[enriquephl]

Summary

Cuts v0.5.0. Pure version-bump PR — all content already promoted into main via #58.

Workspace + 5 path-dep pins moved from 0.4.3-dev to 0.5.0. openapi.json regenerated (info.version follows CARGO_PKG_VERSION). README docker-pull examples bumped (:0.4.1 → :0.5.0).

Why 0.5.0 (not 0.4.30 or 0.4.3)

Previous published crates land at 0.4.21. crates.io requires strictly-increasing semver, so stylized 0.4.3 would fail the registry's ordering check. v0.5 jumps cleanly past and also reflects the substance of this cut:

• New metadata audit surface on chat_messages (raw scope/traits on user rows; resolved on assistant rows)
• New schema columns from migrations 0019 (tip marker + filter audit) + 0020 (error_handling_config)
• System-prompt rewrite (ASCII headers, [recent_conversation] short-term memory, iron rules ⓪/③)
• chat_output_filter validity gate + fail-open audit
• Pseudo-ghost on chain exhaustion

Test plan

• cargo build --workspace clean
• cargo clippy --workspace --all-targets -- -D warnings clean
• cargo fmt --all --check clean
• cargo test --workspace — 447 passed
• openapi.json regen → info.version = 0.5.0
• No stray 0.4.x literals in Cargo.toml / Cargo.lock / openapi.json / README

Post-merge ops (you drive)

After this PR squash-merges:

1. fetch + reset local main to the squashed commit
2. git tag -s v0.5.0 -m "..."; verify with git tag -v v0.5.0; push tag → triggers GHCR amd64 build
3. gh release create v0.5.0 (full release, NOT prerelease) with Features / Migrations notes
4. cargo publish -p eros-engine-core → -p eros-engine-store → -p eros-engine-llm

🤖 Generated with Claude Code