feat(bootstrap): lifecycle logging with AppName, versions and registration summary

[tgiachi]

Summary

The bootstrap was silent: nothing on service start, nothing on shutdown, no trace of registrations, and a start failure propagated without naming the service. Now the whole lifecycle is logged:

MyApp 1.0.0 starting (SquidStd 0.15.0, config myapp, root /srv/myapp)
Registered 7 lifecycle service(s), 5 config section(s), 25 container registration(s)
Started JobSystemService in 2.6ms
MyApp started: 5 service(s) in 30.1ms
...
MyApp stopping (5 service(s))
Stopped MetricsCollectionService
MyApp shutdown complete

• SquidStdOptions.AppName (defaults to the entry assembly name) + app/SquidStd versions from InformationalVersion; attached to every event as Application/ApplicationVersion enrichment.
• Logger configured before the service loop (was mid-loop after the config manager - earlier services' logs were dropped by the silent logger).
• Registration summary: Information counts + Debug detail (lifecycle services with priorities, config sections, full DryIoc container snapshot grouped by assembly) - zero changes to the 38 registration extensions, all read from already-tracked data.
• Per-service start with duration; a failing start logs an Error naming the service, then rethrows.
• Shutdown with continue-on-error: a failing StopAsync logs a Warning and the remaining services are still stopped (was: aborted the loop, leaving them running); cancellation still rethrows.
• Container-provided sinks: ILogEventSink instances registered in the container are attached to the bootstrap logger (extension point + what makes these tests possible).
• Docs paragraph in the bootstrap-lifecycle concept.

Follow-ups noted (out of scope)

• Pre-existing double-start: StartAsync called twice re-starts every service (the GettingStarted sample does StartAsync + RunAsync); MarkStarting should guard it.
• Stop-cancel leaves remaining services unstoppable (state already Stopped); acceptable, documented behavior.

Test Plan

• 7 lifecycle tests (banner/enrichment, AppName default+override, registrations, per-service, pre-config-manager priority capture, failure Error + rethrow, stop continue-on-error, shutdown complete)
• Full suite 1011/1011; build 0 errors, 0 new warnings; docfx 0 warnings
• Manual smoke on a file-based app: full lifecycle visible in console
• No BREAKING markers in commits (expected release: 0.16.0)