PrivacyAwareAnalyticsSampler class

Decorator over a real AnalyticsProvider (FEAT-83) combining 3 privacy/ volume controls, each independently audit-countable via auditSnapshot:

1. Consent gate — same default-deny rule ConsentGatedAnalyticsProvider already enforces (no ConsentStateService registered, or ConsentCategory.analytics not ConsentStatus.granted, drops the event). Duplicated here (not composed via that decorator) so this class stays a single drop-in registration point with one combined audit trail — analyticsProvider.dart's own contract makes the check itself trivial (1 line), so the duplication costs nothing real.
2. Deterministic sampling — sessionSeed (defaults to AppSessionTracker.current's sessionId) + the event name are hashed via fnv1aHash into a stable bucket, so the SAME event name within the SAME session always gets the SAME keep/drop decision. This matters for funnel counts: a per-call coin flip would let event #1 of a repeating action survive while event #2 in the same session silently vanishes, corrupting any per-session aggregate. defaultSamplingRate applies unless samplingRateOverrides names that event specifically.
3. PII redaction, before anything else downstream — when registry is supplied, every event is validated through it (same SdkEventSchemaRegistry FEAT-77 already ships) BEFORE the rate-limit check and BEFORE reaching AnalyticsProvider itself — a pii-marked field, or an outright schema rejection, never reaches the rate limiter's counters or the real provider.
4. Rate limit / backpressure — a fixed-window counter (maxEventsPerWindow per windowSize); once the window's budget is spent, further events in that window are dropped immediately (AnalyticsDropReason.rateLimited) rather than buffered — gameplay code calling logEvent never blocks or awaits anything, and an unbounded buffer that never gets flushed (e.g. offline) can never grow — dropping IS the backpressure, not a queue with its own lifecycle to manage.

A throwing inner provider is caught and forwarded to CrashReporter.maybe (same contract SchemaValidatedAnalyticsProvider already uses) — never crashes gameplay code.