Problem: malformed legacy transcript baselines could crash the Desktop service while startup migration restored a nil projection.
Root cause: session runtime construction discarded NewProjection errors and continued into RestoreRuntime without a valid projection.
Fix: propagate typed initialization failures, release session ownership on every failed path, keep healthy migrations running, add content-free local diagnostics, and queue a deduplicated telemetry-gated exception for the crash dashboard.
Verification: session and transcript package suites, focused Desktop crash/migration tests, targeted race tests, crash worker tests, and worker typecheck pass.
