chore: post-refactor housekeeping + P1 fixes (#59, #71, #72)

[variablefate]

Housekeeping + three deferred P1 fixes from the #65/#66/#67 refactor arc. Split into focused commits for easier review.

Scope

Code/docs

• c00c3a1 docs: reflect post-refactor coordinator + screen-component architecture — .claude/CLAUDE.md updated to reflect the four refactor PRs that landed today (feat(coordinator): extract rider protocol logic into :common coordinators #70, refactor(drivestr): extract AvailabilityCoordinator, AcceptanceCoordinator, RoadflareDriverCoordinator #69, refactor: decompose high-churn Compose screens into focused components #68, refactor(roadflare-rider): extract RideTab state-binding components #73). Adds the six new :common/coordinator/ files to the Quick Implementation Status table, catalogs the per-module components/ packages in Key Files Reference, and flags coordinators as synthetic hotspots requiring extra care on first bug fixes.
• (no commit) Untracked stale rider-app copies deleted from the main-repo checkout: rider-app/src/main/java/com/ridestr/rider/viewmodels/AvailabilityMonitorPolicy.kt and its test. PR feat(coordinator): extract rider protocol logic into :common coordinators #70 moved the canonical copy to :common/coordinator/; the stale copies were untracked local files flagged in the 2026-04-18 triage. Byte-diffed first — only delta is the expected API migration (RideStage → isWaitingForAcceptance: Boolean, dropped SHOW_UNAVAILABLE variant). No commit needed since they were never tracked in git.

P1 fixes

• 40a2e8b fix: show placeholder in SATS mode when BTC price is unavailable (#72) — Adds formatSatsOrPlaceholder helper in :common/fiat/FiatFareFormatting. Applied to formatFareAmount (RideTabComponents) + formatFareUsd (DriverSelectionScreen), both of which previously fell back silently to $X.XX USD when BitcoinPriceService hadn't populated a price. Verified that HistoryStatsCard.totalSpentDisplay and RideHistoryEntry.formatFareDisplay do NOT have this bug (their SATS branch reads fareSats directly). Unit test pins the contract. Closes bug: formatFareAmount SATS mode silently falls back to USD when price unavailable #72.

• 3c0a63e perf: reduce recomposition cost in DriverMode offer cards (#71) — Five-part fix:

  1. RelativeTimeText leaf composable isolates the 1Hz ticker from card bodies. Route math, earnings, and findBestCommonFiatMethod no longer re-run per second.
  2. Derived values (pickupDistanceKm, pickupDurationMin, earnings strings, payment-match state) wrapped in keyed remember blocks. Earnings logic factored into EarningsDisplay + computeEarningsDisplay; payment-match into a PaymentMatchDisplay sealed class.
  3. items { } lambdas hoisted via remember(offer, callback) { ... }; items(key = { it.eventId }) added so LazyList stays aligned.
  4. RideOfferData, BroadcastRideOfferData, FiatFare, RouteResult, FollowedDriver annotated @Immutable (pure value types whose List<T> fields cause default-unstable inference).
  5. Same remember(deps) pattern applied to HistoryEntryCard.fareDisplay / pickupDisplay / dropoffDisplay, HistoryStatsCard.totalSpentDisplay, and DriverCard.distanceMiles.

  Not addressed in this PR: Map<String, RouteResult> / List<T> params at the OfferInbox / RoadflareFollowerList boundary remain intrinsically unstable. Fixing that would require adding kotlinx.collections.immutable (new cross-cutting dep) or wrapper @Immutable classes for every collection param — filed as follow-up observation below. Closes perf: Reduce recomposition cost in DriverMode offer cards #71.

• 035c51c fix: contextual cancel-warning text for fiat/RoadFlare rides (#59) — CancelDialogStack now takes a PaymentPath parameter. Cashu HTLC rides (SAME_MINT / CROSS_MINT) keep the existing "driver can still claim the fare / no refund guaranteed" text. Fiat / NO_PAYMENT rides get new text: "Cancel This Ride? / Your driver has been notified and may already be on the way." Trigger condition (preimageShared || pinVerified) unchanged — pinVerified still surfaces the dialog for fiat rides, just with honest language. Closes Cancel warning incorrectly mentions payment claiming for fiat/RoadFlare rides #59.

Follow-up observations

None filed as GitHub issues yet — noting here so they're not lost:

• Map/List collection stability at component boundaries (OfferInbox, RoadflareFollowerList, FollowedDriverList). Options: add kotlinx.collections.immutable dependency, or define @Immutable wrapper data classes. Gate on whether the Compose profiler shows measurable cost from those parents' recompositions after this PR lands — if the leaf ticker + inner remember blocks are the dominant cost, the collection-stability work may not be needed.

Closes

• Closes Cancel warning incorrectly mentions payment claiming for fiat/RoadFlare rides #59
• Closes perf: Reduce recomposition cost in DriverMode offer cards #71
• Closes bug: formatFareAmount SATS mode silently falls back to USD when price unavailable #72

Test plan

• ./gradlew :common:testDebugUnitTest passes (adds SatsPlaceholderTest)
• ./gradlew :rider-app:assembleDebug :drivestr:assembleDebug :roadflare-rider:assembleDebug — all three apps assemble clean
• Manual: SATS-mode fare surfaces show — sats placeholder on a cold start (before BTC price fetch), not a $X.XX string
• Manual: Cancel a Cashu ride mid-flight after PIN → "Payment Already Sent" dialog with refund-guarantee language
• Manual: Cancel a fiat/RoadFlare ride mid-flight after PIN → "Cancel This Ride?" dialog without claim language
• Manual: Offer inbox with 5+ broadcast requests visible → ticker updates per second without the full card subtree recomposing (inspect via Layout Inspector / Compose recomposition counts)

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[variablefate]

Code review — First pass

Scanned the PR with five parallel agents (CLAUDE.md compliance, shallow bug scan, git-history review, prior-PR feedback, code-comment compliance). Surfaced five findings. Using the verify-and-fix filter (improve-codebase / lower-entropy / fix-bug; any yes → advance):

Advanced + fixed in 5e43ae3:

1. Child-side remember(offer, onAccept) { ... } wrappers defeated by unstable parent lambdas. DriverModeScreen was passing fresh { viewModel.acceptOffer(it) } per recompose at DriverModeScreen.kt#L575-L577 and #L592-L596. That meant the child remembers added in 3c0a63e invalidated every frame — strictly worse than inline lambdas. Fixed by hoisting six per-offer callbacks to remember(viewModel) { ... } before the Crossfade, so child-side remember(offer, onAccept) blocks now hold across recompositions.
2. Triple destructuring in CancelDialogStack. Positional val (title, body, footer) = Triple(...) is opaque and allocates per recompose. Replaced with three explicit vals assigned inside the if/else.

Verified false-positive (no change needed):

3. formatFareAmount SATS→USD fallback change — this IS the fix requested by #72 acceptance criteria ("not a $X.XX string"). Not a regression.
4. computeEarningsDisplay dropped pickupDistanceKm null guard — false positive. pickupDistanceKm and pickupDurationMin both project from the same pickupRoute?, so they're null-equivalent by construction. The ?: 0.0 fallback is dead defensive code; earnings math is unchanged.
5. @Immutable on RouteResult with List<Maneuver> — verified. Maneuver is a data class with all-val primitive fields, so the contract holds.

Build green on 5e43ae3 (:common:testDebugUnitTest + three :assembleDebug targets).

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[variablefate]

Code review — Pass 2 (convergence)

Pass 2 focused on the 5e43ae3 review-fix commit. No new issues:

• remember(viewModel) { ... } is an appropriate stabilization key — Hilt ViewModels are NavBackStackEntry-scoped and identity-stable across recomposition.
• Both CancelDialogStack if/else branches assign all three vals; definite-assignment holds, footer: String? nullability preserved.

Converged. Marking ready-for-review.

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[variablefate]

Code review — Third pass

Fresh scan against tip 5e43ae3 with five parallel agents (CLAUDE.md compliance, shallow bug scan, git-history review, prior-PR feedback, code-comment compliance).

New findings: none.
Advanced: none.
Verified false / not applicable: n/a — nothing surfaced.
Fixed: n/a.

Specific things spot-checked this pass:

• Stable-lambda hoisting in DriverModeScreen.kt#L520-L529 — remember(viewModel) { ... } key is correct (Hilt VMs are NavBackStackEntry-scoped, identity-stable across config changes). First and only stabilization attempt in this file, no convention conflicts.
• Child-side remember(offer, onAccept) wrappers in OfferInbox / RoadflareFollowerList — now actually hold, since parent identities are stable.
• key(offer.eventId) { ... } inside RoadflareFollowerList.forEach — correctly isolates per-item remember state; items(key = { it.eventId }) collision-safe (eventIds are event SHA-256s).
• Helper extractions (handleOfferAccept, computeEarningsDisplay, computePaymentMatch) — logic preserved, no off-by-one, no stale captures.
• CancelDialogStack paymentPath branching and if/else val assignment — definite-assignment holds, footer: String? nullability preserved.
• Prior-PR deferred items from refactor: decompose high-churn Compose screens into focused components #68/refactor(drivestr): extract AvailabilityCoordinator, AcceptanceCoordinator, RoadflareDriverCoordinator #69/feat(coordinator): extract rider protocol logic into :common coordinators #70/refactor(roadflare-rider): extract RideTab state-binding components #73 — none left unincorporated; the one documented follow-up (Map/List collection stability) is captured in the PR body.

Converged. Keeping PR ready-for-review.

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