fix(deeplink): resolve tip card deeplinks on cold launch

[bmc08gt]

Problem

Tip-card deeplinks (tip/{userId}) are silently dropped on a cold app launch. They work fine when the app is already running (warm launch). Cash links, which went through the same cold-launch hardening earlier, are unaffected.

Root cause

On cold launch, MainRoot.buildNavGraphForLaunch bundles a tip-card deeplink into pendingAction (alongside OpenCashLink and Login) and MainRoot fires it eagerly through App.kt's onPendingAction callback. But that callback only handled OpenCashLink and Login — PresentTipCard fell into the no-op else branch and was dropped. The subsequent deepLink = null then erased the link before the fallback LaunchedEffect(deepLink, currentRoute) (which does handle PresentTipCard) could recover it.

Warm launches are past Loading, so the fallback effect processes the link directly — which is why the bug only shows on cold start.

The gap was introduced in c46c130 (#1127): it wired PresentTipCard into buildNavGraphForLaunch and the fallback effect, but not the eager onPendingAction dispatcher.

Fix

Add the missing PresentTipCard branch to onPendingAction so it calls session.resolveTipCard(userId) eagerly, mirroring the cash-link path. One line, exactly matching the already-working fallback handler.

Testing

• Traced the full cold-launch deeplink flow end-to-end; the downstream TipCardDelegate → BillPresentationDelegate chain is sound and only ever lacked the resolveTipCard call.
• The new branch call is identical to the already-verified warm-path handler.