chore: android technical housekeeping

[ovitrif]

Goal

Bring Bitkit Android's engineering foundation to a current, internally consistent state through independently owned maintenance issues with explicit dependencies, measurable acceptance criteria, and product-level verification.

GitHub's native sub-issue relation is the source of truth for child scope and completion. The Kotlin/Compose child also specifies two follow-up issues for version-specific AI rules and current-language-feature code style. The Navigation 3 child owns an ordered series of separate-concern pull requests.

Dependency order

1. chore: update readme and agent instructions #1117
   Can land independently.
2. chore: update kotlin and compose bom #1115
   • Updates Kotlin and Compose on current AGP 8.13.2
   • Establishes the Kotlin 2.3.21 or newer baseline required by chore: upgrade to agp 9 and configure parallelism #1114
   • Starts its agent-rule and code-style follow-ups after chore: update readme and agent instructions #1117 lands
3. chore: upgrade to agp 9 and configure parallelism #1114
   Upgrades AGP, Gradle, KSP, Hilt, parallelism, and artifact publication from the landed Kotlin/Compose baseline.
4. chore: update third-party dependencies #1116
   Incorporates the landed Kotlin/Compose and AGP/KSP/Hilt outcomes into the catalog audit.
5. refactor: migrate incrementally to navigation 3 #1118
   Implementation starts from the settled toolchain and dependency catalog.

Ownership

• Each direct child owns one coherent concern and its verification evidence.
• Each child or follow-up issue owns one implementation pull request, except:
  • refactor: migrate incrementally to navigation 3 #1118
• chore: upgrade to agp 9 and configure parallelism #1114
  Owns directly coupled artifact paths and build/release documentation.
• chore: update readme and agent instructions #1117
  Owns generic AI guidance, rule architecture, and agent-facing command discovery.
• chore: update kotlin and compose bom #1115
  Its rule follow-up owns version-specific language and Compose guidance.

Acceptance criteria

• Each pull request is reviewed, approved, validated, and merged independently.
• Navigation 3 lands through the ordered incremental series with a runnable, tested app after every merge.
• Final master passes the combined build, test, lint, device, E2E, journey, release, and documentation checks applicable to the changed surfaces.
• The Bitkit project item reaches ✅ Done after acceptance, review, check, and merge gates complete.