release: UsageHub v0.8.7

[tttboy123]

Summary

• publish UsageHub 0.8.7 (build 29) with current refresh and quota fixes
• extend the bounded desktop refresh window so long successful refreshes are not reported as failures
• wait one 30-minute interval before the first automatic menu-bar refresh and defer provider credentials until refresh is due
• make Windows tests platform-safe and align the Linux release observer with the 30-minute service schedule without weakening the zero-network/zero-keychain boundary
• update release metadata and documentation

Verification

• Python: 2095 passed, 26 skipped
• Desktop: 120 passed; npm audit: 0 vulnerabilities
• Web: full tests and production build passed; production npm audit: 0 vulnerabilities
• Dependency audit: no known vulnerabilities
• DMG: hdiutil verify + mounted release artifact audit passed; package identity 0.8.7 (29)
• User-side: cold startup remained read-only until a user action; Capacity page-entry refresh completed successfully; Codex weekly capacity updated from 75% to 73%
• Linux x64: native release build and frozen Observer topology canary passed with the 1800-second service schedule

Artifact

• UsageHub-0.8.7-mac-arm64.dmg
• SHA-256: 43d8d23c501b40f895c0e9c0696c9f37e8d60166bb6a21c3a80a6ab944423956