Fix Explorer project selection and Review Queue sync

[blancmathis]

Summary

• make one Explorer project click update Explorer, the URL, and the Review Queue project filter immediately
• keep Shared refresh in the background and restore the previous selection, filter, and URL on failure
• document the synchronized selection contract
• release as 0.6.17 on top of merged PR Fix persistent Explorer file navigation #37 / 0.6.16

Validation

• regression test failed before the fix with Review Queue stuck on All projects
• targeted source contract test passed
• 8/8 targeted browser regressions passed on Chromium desktop/mobile, Firefox, and WebKit
• adjacent in-flight project/worktree selection scenarios passed
• full local suite before integration: 60/60 test processes passed
• package privacy check passed
• npm audit reported 0 vulnerabilities
• npm pack --dry-run passed
• Context Room doctor passed