chore(release): 0.7.0

[willytop8]

Summary

• release the lifecycle-feedback work as 0.7.0
• move the completed entries from Unreleased into the dated release section
• clarify that the v0.6.6 custom-command presentation column is historical
• record the separate OpenCode 1.18.11 host-integration canary accurately

Why

PR #50 added public lifecycle-message options and observable status behavior, so
the compatibility policy calls for a minor release. The README clarification
prevents the historical v0.6.6 provider matrix from reading like the current
package version or a current feature state.

Verification

• npm run release:check — passed
• tests — 350/350
• coverage — 98.34% lines, 90.49% branches, 90.44% functions
• mutation contract — 67/67 critical mutants killed
• behavior benchmark — 100/100
• packed host/tool contracts and installation verifier — passed
• production dependency audit — zero vulnerabilities
• exact npm tarball — 24 expected files; clean consumer passed both export paths
• real OpenCode 1.18.11 canary against the exact tarball — passed lifecycle,
  status/audit reporting, host logging, privacy, persistence, and cleanup

Release artifact

After this PR merges, create annotated tag v0.7.0 at the merge commit and use
only the tarball produced by the tag-triggered Release Check for npm publication.