[t-regbs]

Why

The repository tracks machine-local state and an old release bundle, while tooling assumes a Python version it does not declare. Remove those sources of noise and retain only native outputs consumed by the app.

What changed

• Support Python 3.9 annotations, document interpreter versions, and test 3.9/3.14 in CI.
• Untrack 20 local-state files and the historical AAB; preserve local copies and document the hash-verified archive and Git recovery path.
• Remove unused core frameworks, the Intel target, empty dependency blocks and template comments.

Scope

• Build configuration, Python tooling and repository hygiene. ARM libraries and shared IDE/Xcode configuration remain supported.
• No history rewrite or release-signing changes.

Blast Radius

Native task configuration changes, but the app consumes the retained shared ARM framework. Local files were preserved byte-for-byte before removal from the index; the release archive is local and recoverable from retained Git history.

Verification

• All 30 Python tests and three source gates pass under Python 3.9.6 and 3.14.3.
• Device/simulator ARM compilation passed; combined cleanup passed 526 host and 399 Kotlin native tests, Android assembly/lint, fresh framework export and Swift client compilation and 28 Xcode tests (one expected iPad-only skip).
• Independent review confirmed task inventory, retained configuration and all preservation/archive hashes.