release: v0.17.8

[edwin-zvs]

Patch release bump: 0.17.7 → 0.17.8.

• Bumps [workspace.package] version in Cargo.toml (source of truth) and regenerates Cargo.lock
• Bumps Formula/construct.rb version (macOS checksums follow in a separate PR after the tag builds, since the release workflow's direct push to main is blocked by branch protection)
• brew style clean

Rebased onto latest main so this also ships:

• fix(tui): restore Playbook menu after keyboard selection #1289 fix(tui): restore Playbook menu after keyboard selection
• Playbook editor: render fenced code as coherent blocks #1290 Playbook editor: render fenced code as coherent blocks

After merge: tag the merge commit v0.17.8 and push it to trigger the release workflow.

[edwin-zvs]

Holding this release until two more Playbook editor fix PRs from the Playbook editor enhance session land on main. After they merge I'll rebase this branch and continue with the v0.17.8 tag.

[edwin-zvs]

Rebased onto main to include #1289 and #1290. Waiting on CI, then I'll merge and tag v0.17.8.