v0.5.18

v0.5.18

Fixed

• Fixed TUI key lifecycle handling so Enter repeat/release events cannot immediately confirm modal selections after opening /model.
• Preserved non-Enter repeat behavior for navigation keys like PageUp.
• Added exact slash-command dispatch smoke coverage for /help and /clear.
• Added PTY-backed headless /help smoke coverage that drives the real TUI and verifies slash commands render.

Verification

• PR #49 CI: Check & Lint, Doc, Test (nextest) passed.
• PR #50 CI: Security Audit, Check & Lint, Doc, Test (nextest) passed.
• Local release gate: cargo test --workspace --no-fail-fast — 1802 passed, 13 ignored.