feat: preserve Inspector access during derived rebuilds

[kevinswiber]

Summary

• expose derived-access lifecycle status and progress to Inspector, with explicit cancel and retry controls
• keep valid older generations readable while a replacement builds and offer a bounded authoritative fallback when no derived view is available
• serialize authoritative fallback requests in the client while retaining the server-wide concurrency permit
• latch cancellation until an explicit retry so status and data-route discovery cannot restart a cancelled bootstrap

Validation

• focused lifecycle and Inspector integration tests
• web test suite: 1,028 passed across 46 files
• just web-check
• just check: 3,193 passed, 5 skipped
• just package-archive-selftest: 8 archives passed
• generated Inspector bundle verified current
• native Windows lifecycle and Inspector integration tests