feat: debounce_timing [rn]

[choudlet]

Summary

Adds 2-second debouncing to network reachability online transitions. Offline transitions remain immediate. This prevents circuit breaker resets, wasteful flushes, and churn during rapid network flapping (e.g., tunnel, elevator, weak cell signal).

Ticket: SC-37711

Changes

• src/analytics/network/NetworkReachability.ts — New NetworkStatus type and NetworkReachability interface for network monitoring abstraction
• src/analytics/network/StubNetworkMonitor.ts — Test double with simulate() for synchronous status changes (no internal timers)
• src/analytics/dispatcher.ts — Added resetCircuitBreaker() method for post-reconnect circuit reset
• src/analytics/MetaRouterAnalyticsClient.ts — ONLINE_DEBOUNCE_MS (2s) constant, AnalyticsClientDeps DI interface, debounced onStatusChange callback in setupNetworkMonitor(), cleanup in reset(), network-aware canSend() and getDebugInfo()

Behavioral contract (cross-platform)

Transition	Debounced?	Side-effects
connected → disconnected	No (immediate)	Cancel debounce timer, update networkStatus, dispatcher sees offline via canSend()
disconnected → connected	Yes (2s)	After 2s stable: update networkStatus, reset circuit breaker, flush
Rapid flap ending offline	No	Single offline, zero online events
Rapid flap ending online	Yes (2s from last)	Timer resets each cycle; only final stable connected triggers flush

During the 2s debounce window, canSend() returns false so periodic/threshold flushes are blocked.

Public API

No changes. Entirely internal. No new config options or methods. The AnalyticsClientDeps second constructor arg is optional and only used for DI in tests.

Test plan

• Rapid flapping produces single flush (not one per transition)
• Debounce timer cancelled when device goes back offline
• Clean online transition flushes after exactly 2s
• Offline transition is immediate (not debounced)
• reset() cancels pending debounce timer
• Default connected status when no monitor is provided
• All 168 existing tests pass (zero regressions)

🤖 Generated with Claude Code

[choudlet]

Closing — rebasing debounce work onto the network reachability infrastructure branch instead.