feat(android): Splash Screen API plumbing (Android 12+)

[ilmoniemi]

User Story

As a Pyrycode mobile installer, I want a proper splash screen on app launch, so the app feels polished and matches platform conventions.

Context

Plan Phase 5 lists splash screen (Android 12+ Splash Screen API). The androidx.core:core-splashscreen compat library backports the same configuration surface to Android 6+, so a single setup covers all supported devices.

This ticket lands the plumbing only — dependency, splash theme, manifest wiring, MainActivity install call, and a minimal placeholder vector icon. No animation logic, no branded artwork, no timing hacks. Real branded splash (final icon + animated transition) is a deliberate follow-up to be filed once visual design lands.

The launch-time start-destination decision (Welcome vs. Channel List) was wired in #13 (closed) and must keep working unchanged — splash hands off to the existing NavHost.

Acceptance Criteria

• App launches showing the splash on a brand-colored background with a placeholder vector icon, then transitions to the conditional start destination from feat(ui): conditional NavHost start destination based on paired-server-exists #13 (Welcome on fresh install, Channel List once pairedServerExists is true) with no visible flash, gap, or duplicate frame between splash and first screen.
• No artificial timeout, sleep, or minimum-duration delay — the system controls when the splash dismisses.
• ./gradlew assembleDebug and ./gradlew lint pass with no new warnings.
• Manually verified on an Android 13+ emulator; PR body notes any Android 11/12 fallback behavior if an emulator was available for that range.

Technical Notes

The architect picks the exact mechanism, but the surface is well-known:

• Add androidx.core:core-splashscreen via gradle/libs.versions.toml and reference it from app/build.gradle.kts.
• Define a Theme.SplashScreen style in res/values/themes.xml with windowSplashScreenAnimatedIcon pointing at a new placeholder vector drawable, and windowSplashScreenBackground set to a brand color from colors.xml.
• Set the launcher <activity> theme in AndroidManifest.xml to the splash theme (the application-level theme stays as today's Theme.PyrycodeMobile, which the activity switches to via installSplashScreen()).
• Call installSplashScreen() in MainActivity.onCreate before super.onCreate(...).

Out of Scope

• Branded icon, animated transition, exit-animation listeners — follow-up ticket once visual design lands.
• Splash-time data preloading or gated setKeepOnScreenCondition { ... } logic — explicitly not needed; feat(ui): conditional NavHost start destination based on paired-server-exists #13's conditional start destination already avoids a flash without splash-side gating.

Figma

N/A — placeholder vector icon on brand color; real branded splash (final mark + transition) is a deliberate follow-up to be filed under Phase 5 polish.

Size Estimate

S — one dependency wiring, one theme style, one new vector drawable, one manifest attribute, one MainActivity line. Coupled steps that produce a usable splash only when landed together; splitting would create unbuildable or empty-splash intermediate states.

[ilmoniemi]

🤖 Product Owner — creates structured issues

po agent has completed work on this ticket.

Agent output (click to expand)

Refinement complete on #80.

**What changed:**
- **ACs tightened 7 → 4** — collapsed the four step-by-step wiring criteria (dep / theme / manifest / `installSplashScreen()`) into one behavior AC ("launches showing splash → hands off to #13's start destination with no flash"), since they all restate the same single concern and a partial implementation can't ship.
- **Wiring details moved to `## Technical Notes`** as pointers for the architect (where they belong — not as acceptance criteria).
- **Figma block** rewritten in the canonical `N/A — <justification>` format. Splash *is* UI-visible so the section is required; the placeholder + deferred branded follow-up is a legitimate use of the N/A escape.
- **Added `## Out of Scope`** to fence off branded artwork, exit-animation listeners, and splash-time data preloading — common scope creep traps the architect or developer might otherwise rationalize in.
- **Sizing rationale** spelled out at the bottom: S is correct because the steps are tightly coupled (no usable intermediate state), so the always-split patterns don't fire.

Not security-sensitive (no auth/header/crypto/network surface), so no `security-sensitive` label.

Labels: `size:s` applied. `wip:po` is the dispatcher's in-flight marker; it will swap to `ready:po` automatically on successful exit.

Ready for human review. Move to the next column when approved.

[ilmoniemi]

Blocked by #83: both branches modify gradle/libs.versions.toml. #83 adds ktlint / spotless entries under [versions] and a spotless plugin entry; #80 needs to add a coreSplashscreen version under [versions] and an androidx-core-splashscreen library entry. Both insertions target the same hunks (end of [versions] and the libraries / plugins blocks), so concurrent merges would conflict.

Will write the spec once #83 lands.

(Detected by architect file-overlap check via git diff origin/main...origin/feature/83.)

[ilmoniemi]

🤖 System Architect — defines Go interfaces, data flows, concurrency patterns

architect agent flagged issues on this ticket → rework by po.

Agent output (click to expand)

Blocked #80 on #83 and routed back to PO. Both tickets edit `gradle/libs.versions.toml` in the same hunks (`[versions]` block + libraries / plugins blocks): #83 adds `ktlint` + `spotless` entries, #80 needs `coreSplashscreen`. Concurrent merges would conflict, so per the file-overlap rule I set `addBlockedBy(#80, #83)`, commented on #80, applied `needs-rework:po`, and left the worktree untouched. The ticket will auto-advance back to Backlog and re-enter architecture once #83 lands.

Needs rework by po. See agent findings above.