Add optional SKILL.md review and prepare 0.7.0

[Giorgio Ughini (GiorgioUghini)]

Target

Target the active release/0.6.0 branch. This is the feature merge; the subsequent release merge will target main.

Changes

• Add optional, read-only Review SKILL.md beside skill install/export actions for every skill destination.
• Prepare the complete rendered file without writing it, then install/export those exact bytes without a second model turn.
• Share placement, progress, errors and completion between the modal and main screen. A placement from either surface completes both.
• Preserve the existing direct one-click install/export flow, invalidate previews after plan edits, and handle cancellation, expired previews and retries.
• Leave automation creation and tool-permission policy unchanged.
• Prepare package and lockfile version 0.7.0; no dependency or installer changes.

Validation

• 267 tests pass; production build, eval typecheck, lockfile portability, and the 285-package license inventory pass locally.
• Isolated browser checks cover modal and main placement, direct installation, export-only destinations, preview reuse/invalidation, long text, accessibility, expiration and cancellation races.
• The updated local executable was launched for the requesting user's testing.
• Windows x64/ARM64 and macOS/Ubuntu CI must pass before merge and again on the final main release commit.

Publication

The user authorized committing and publishing the next release. Follow RELEASING.md: source-only publication, immutable annotated tag, exact commit-pinned commands and installer SHA-256 hashes. No binary attachments.