Kotlin, Compose and Material 3 project skeleton that builds and launches #2

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opened 2026-08-18 02:14:36 -05:00 by null · 0 comments

null commented

2026-08-18 02:14:36 -05:00

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There is no Android project. Everything else in Batch 01 needs one, and so do the hooks — a pre-commit hook with nothing to run is not a guard.

What this covers:

Gradle Kotlin DSL with a version catalog at gradle/libs.versions.toml
four modules: app, core/designsystem, domain/cycle, domain/prediction
domain/* are kotlin("jvm") and cannot see the Android SDK — PRODUCT_PLAN.md §57.10 requires the engine to be testable without Android, and a module that cannot compile against it is a stronger guarantee than a convention
Material 3 theme with centralized colour tokens (§39 palette), light and dark
the four-tab navigation shell from §20, with placeholder screens that say so
Hilt wired now, because retrofitting DI across modules later is the expensive order
a placeholder launcher icon as a vector behind a replaceable resource name, which §42 explicitly sanctions — unlike docs/data/img/, where a placeholder must never be made

Two traps that cost time here:

AGP 9 has built-in Kotlin support. Applying org.jetbrains.kotlin.android is now an error, not a redundancy. The Compose compiler plugin is still applied separately.
Versions are verified, not inherited. PRODUCT_PLAN.md asks for current stable versions to be checked against the official Android/Kotlin documentation at implementation time rather than pinned from its own text. Do that again before changing them.

Verify: ./gradlew test passes, ./gradlew assembleDebug and ./gradlew assembleRelease both succeed, and the app launches to the Today tab with all four tabs reachable.

There is no Android project. Everything else in Batch 01 needs one, and so do the hooks — a pre-commit hook with nothing to run is not a guard. What this covers: - Gradle Kotlin DSL with a version catalog at `gradle/libs.versions.toml` - four modules: `app`, `core/designsystem`, `domain/cycle`, `domain/prediction` - `domain/*` are `kotlin("jvm")` and **cannot see the Android SDK** — PRODUCT_PLAN.md §57.10 requires the engine to be testable without Android, and a module that cannot compile against it is a stronger guarantee than a convention - Material 3 theme with centralized colour tokens (§39 palette), light and dark - the four-tab navigation shell from §20, with placeholder screens that say so - Hilt wired now, because retrofitting DI across modules later is the expensive order - a placeholder launcher icon as a vector behind a replaceable resource name, which §42 explicitly sanctions — unlike `docs/data/img/`, where a placeholder must never be made Two traps that cost time here: - **AGP 9 has built-in Kotlin support.** Applying `org.jetbrains.kotlin.android` is now an error, not a redundancy. The Compose compiler plugin is still applied separately. - **Versions are verified, not inherited.** PRODUCT_PLAN.md asks for current stable versions to be checked against the official Android/Kotlin documentation at implementation time rather than pinned from its own text. Do that again before changing them. Verify: `./gradlew test` passes, `./gradlew assembleDebug` and `./gradlew assembleRelease` both succeed, and the app launches to the Today tab with all four tabs reachable.