Migrate to Kotlin DSL, Compose, and modern Android stack

.gitignore

@@ -13,7 +13,18 @@ local.properties
 projectFilesBackup/
 project.properties
 .gradle
+.kotlin
 release.keystore
 com_crashlytics_export_strings.xml
 crashlytics-build.properties
 crashlytics.properties
+
+# Xcode
+xcuserdata/
+*.xcscmblueprint
+DerivedData/
+
+metrodroid/
+metrodroid-commits/
+
+*.hprof

.gitmodules

@@ -1,3 +0,0 @@
-[submodule "third_party/nfc-felica-lib"]
-	path = third_party/nfc-felica-lib
-	url = https://github.com/codebutler/nfc-felica-lib.git

CLAUDE.md

@@ -0,0 +1,146 @@
+# CLAUDE.md — Project Rules for FareBot
+
+## Project Overview
+
+FareBot is a Kotlin Multiplatform (KMP) Android/iOS app for reading NFC transit cards. It is being ported from/aligned with [Metrodroid](https://github.com/metrodroid/metrodroid).
+
+**Metrodroid source code is in the `metrodroid/` directory in this repo.** Always use this local copy for comparisons and porting — do not fetch from GitHub.
+
+## Critical Rules
+
+### 1. NEVER lose existing features
+
+When refactoring, rewriting, or porting code: **every existing feature must be preserved**. Before modifying a file, understand what it currently does. After modifying it, verify nothing was lost. Do not silently drop functionality — if something must change, say so explicitly.
+
+Common regressions to watch for:
+- Missing UI elements (images, buttons, screens)
+- Lost navigation paths (menu items, long-press handlers)
+- Removed data fields from transit info display
+- Broken sample data loading
+
+### 2. No stubs — use serialonly for identification-only systems
+
+Do NOT create stub/skeleton transit implementations that only show a card name and serial number **when Metrodroid has a full implementation available to port**. If Metrodroid has trip parsing, balance reading, subscriptions, or other features for a system, port all of it — never reduce a full implementation to a stub.
+
+For systems where Metrodroid itself only supports identification (card name + serial number) with no further parsing, use `farebot-transit-serialonly/` — matching Metrodroid's `serialonly/` directory. These extend `SerialOnlyTransitInfo` and provide a `Reason` (LOCKED, NOT_STORED, MORE_RESEARCH_NEEDED) explaining why data isn't available.
+
+If a full implementation can't be ported yet (e.g., missing infrastructure framework), don't add the system at all until the dependency is ready.
+
+### 3. Faithful ports from Metrodroid
+
+When porting code from Metrodroid: **do a faithful port**. Do not simplify, abbreviate, or "improve" the logic. Port ALL features, ALL edge cases, ALL constants. After writing each file, diff it against the Metrodroid original to verify nothing was missed.
+
+- `ImmutableByteArray` → `ByteArray`
+- `Parcelize`/`Parcelable` → `kotlinx.serialization.Serializable`
+- `Localizer.localizeString(R.string.x)` → `stringResource.getString(Res.string.x)`
+- `Timestamp`/`TimestampFull`/`Daystamp` → `kotlinx.datetime.Instant`
+- `TransitData` → `TransitInfo`
+- `CardTransitFactory` → `TransitFactory<CardType, TransitInfoType>`
+
+Do NOT:
+- Skip features "for later"
+- Change logic unless there's a concrete reason
+- Remove constants, enums, or data that exist in the original
+- Simplify switch/when statements by dropping cases
+
+### 4. Debug systematically, not speculatively
+
+When something is broken: **add logging and diagnostics first**. Do not guess at fixes. The workflow should be:
+
+1. Add debug logging to understand what's actually happening
+2. Read the device console output
+3. Identify the root cause from actual data
+4. Fix the specific problem
+5. Remove debug logging
+
+Do NOT make speculative changes hoping they fix the issue. Each failed guess wastes a round.
+
+### 5. All code in commonMain unless it requires OS APIs
+
+Write all code in `src/commonMain/kotlin/`. Only use `androidMain` or `iosMain` for code that directly interfaces with platform APIs (NFC hardware, file system, UI system dialogs). No Objective-C. Tests use `kotlin.test`.
+
+### 6. Use StringResource for all user-facing strings
+
+All user-facing strings must go through Compose Multiplatform resources:
+- Define strings in `src/commonMain/composeResources/values/strings.xml`
+- For UI labels in `TransitInfo.getInfo()`, use `ListItem(Res.string.xxx, value)` or `HeaderListItem(Res.string.xxx)` directly
+- For dynamic string formatting, use `runBlocking { getString(Res.string.xxx) }`
+- Legacy pattern: Pass `StringResource` to factories — still works but not required for new code
+
+Example patterns:
+```kotlin
+// Preferred for static labels
+ListItem(Res.string.card_type, cardType)
+HeaderListItem(Res.string.card_details)
+
+// For dynamic values
+val formatted = runBlocking { getString(Res.string.balance_format) }
+```
+
+Do NOT hardcode English strings in Kotlin files.
+
+### 7. Use MDST for station lookups, not SQLite .db3
+
+Station databases should use the MDST (protobuf) format via `MdstStationLookup`, not SQLite .db3 files with SQLDelight. All MDST files live in `farebot-base/src/commonMain/composeResources/files/` and are accessed via `MdstStationLookup.getStation(dbName, stationId)`.
+
+Example:
+```kotlin
+val station = MdstStationLookup.getStation("orca", stationId)
+station?.stationName  // English name
+station?.companyName  // Operator name
+station?.latitude     // GPS coordinates (if available)
+```
+
+### 8. Verify your own work
+
+After making changes:
+- Run `./gradlew allTests` to confirm tests pass
+- Run `./gradlew assemble` to confirm the build succeeds
+- If you changed UI code, describe what the user should see
+- If you ported code, diff against the original source
+
+Do NOT claim work is complete without verification.
+
+### 9. Preserve context across sessions
+
+Key project state is in:
+- `/Users/eric/.claude/plans/` — implementation plans (check newest first)
+- `/Users/eric/Code/farebot/REMAINING-WORK.md` — tracked remaining work
+- Session transcripts in `/Users/eric/.claude/projects/-Users-eric-Code-farebot/`
+
+When continuing from a previous session, read these files to recover context rather than starting from scratch.
+
+## Build Commands
+
+```bash
+./gradlew allTests          # Run all tests
+./gradlew assemble          # Full build (Android + iOS frameworks)
+./gradlew :farebot-android:assembleDebug  # Android only
+```
+
+## Module Structure
+
+- `farebot-base/` — Core utilities, MDST reader, ByteArray extensions
+- `farebot-card-*/` — Card type implementations (classic, desfire, felica, ultralight, iso7816, cepas, vicinity)
+- `farebot-transit-*/` — Transit system implementations (one module per system)
+- `farebot-transit-serialonly/` — Identification-only systems (serial number + reason, matches Metrodroid's `serialonly/`)
+- `farebot-transit/` — Shared transit abstractions (Trip, Station, TransitInfo, TransitCurrency, etc.)
+- `farebot-shared/` — Shared app code, Compose UI, ViewModels
+- `farebot-android/` — Android app entry point
+- `farebot-ios/` — iOS app (Xcode project)
+
+## Registration Checklist for New Transit Modules
+
+1. Create `farebot-transit-{name}/build.gradle.kts`
+2. Add `include(":farebot-transit-{name}")` to `settings.gradle.kts`
+3. Add `api(project(":farebot-transit-{name}"))` to `farebot-shared/build.gradle.kts`
+4. Add `implementation(project(":farebot-transit-{name}"))` to `farebot-android/build.gradle.kts`
+5. Register factory in `TransitFactoryRegistry.kt` (Android)
+6. Register factory in `MainViewController.kt` (iOS, non-Classic cards only)
+7. Add string resources in `composeResources/values/strings.xml`
+
+## Kotlin/Native Gotchas
+
+- `internal` types cannot be exposed in public APIs (stricter than JVM)
+- Constructor parameter names matter — use the exact names the data class defines
+- When removing a transitive dependency, add direct `api()` deps for anything that was accessed transitively

Makefile

@@ -0,0 +1,44 @@
+IOS_DEVICE_ID := $(shell xcrun xctrace list devices 2>/dev/null | grep -v Simulator | grep -E '\([0-9A-F-]+\)$$' | grep -v Mac | head -1 | grep -oE '[0-9A-F]{8}-[0-9A-F]{16}')
+IOS_APP_PATH = $(shell ls -d ~/Library/Developer/Xcode/DerivedData/FareBot-*/Build/Products/Debug-iphoneos/FareBot.app 2>/dev/null | head -1)
+
+.PHONY: android android-install ios ios-sim ios-install test clean help
+
+## Android
+
+android: ## Build Android debug APK
+	./gradlew :farebot-android:assembleDebug
+
+android-install: android ## Build and install on connected Android device
+	adb install -r farebot-android/build/outputs/apk/debug/farebot-android-debug.apk
+
+## iOS
+
+ios: ## Build iOS app for physical device
+	./gradlew :farebot-shared:linkDebugFrameworkIosArm64
+	./gradlew :farebot-shared:linkDebugFrameworkIosSimulatorArm64
+	xcodebuild -project farebot-ios/FareBot.xcodeproj -scheme FareBot \
+		-destination 'id=$(IOS_DEVICE_ID)' -allowProvisioningUpdates build
+
+ios-sim: ## Build iOS app for simulator
+	./gradlew :farebot-shared:linkDebugFrameworkIosSimulatorArm64
+	xcodebuild -project farebot-ios/FareBot.xcodeproj -scheme FareBot \
+		-destination 'platform=iOS Simulator,name=iPhone 16' build
+
+ios-install: ios ## Build and install on connected iOS device
+	xcrun devicectl device install app --device $(IOS_DEVICE_ID) "$(IOS_APP_PATH)"
+
+## Tests
+
+test: ## Run all tests
+	./gradlew allTests -x linkDebugTestIosSimulatorArm64 -x linkDebugTestIosX64
+
+## Utility
+
+clean: ## Clean all build artifacts
+	./gradlew clean
+	xcodebuild -project farebot-ios/FareBot.xcodeproj -scheme FareBot clean 2>/dev/null || true
+
+help: ## Show this help
+	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | awk 'BEGIN {FS = ":.*?## "}; {printf "  \033[36m%-15s\033[0m %s\n", $$1, $$2}'
+
+.DEFAULT_GOAL := help