M0: Project bootstrap — workspace and crate skeleton

[bug-ops]

Goal

Initialize Cargo workspace with 4 crates, build infrastructure, and project skeleton.

Scope

• Cargo workspace (virtual manifest, resolver 3, edition 2024)
• 4 crates: zeph-core, zeph-llm, zeph-skills, zeph-memory
• Binary crate (src/main.rs)
• Workspace-level dependency management and lints
• .gitignore, CHANGELOG.md, config/default.toml

Acceptance Criteria

• cargo build succeeds with zero warnings
• cargo clippy -- -D warnings passes
• cargo test passes
• cargo run prints version info
• All 4 crates compile with doc comments
• Workspace deps in root Cargo.toml, features in crate manifests

Child Issues

• Initialize Cargo workspace with 4-crate skeleton #7 Initialize Cargo workspace with 4-crate skeleton

Branch

feat/m0/workspace-bootstrap