[t-regbs]

Why

Alarm equality includes construction-time fields, theme decoding is duplicated, and ViewModel constructors obscure the shared coordinator owner. Scheduling an unsaved alarm also silently selects the newest saved row.

What changed

• Create drafts through Alarm.newAlarm, keep persisted values in equality, and update all draft callers plus Swift's generated copy call.
• Use explicit stable theme storage IDs and inject the existing coordinator directly; remove unused persistence forwarding APIs.
• Reject ID0 before scheduling, while preserving saved identities and negative test fixtures.

Scope

• Shared model, preferences, ownership and their Android/Swift callers. Database schema and durable recovery behavior are unchanged.
• Existing uncommitted audio work is excluded and was checked separately for compatibility.

Blast Radius

The generated Swift copy signature and internal ViewModel constructor change. Theme IDs remain LIGHT=0, DARK=1, SYSTEM=2 with invalid values using SYSTEM; every production scheduling caller supplies a saved identity.

Verification

• Reproduced the ID0 fallback before fixing it; added alarm equality, mapper round-trip and theme persistence regressions.
• Combined cleanup passes 526 host and 399 Kotlin native tests, Android assembly/lint, fresh framework export and Swift compilation; 28 Xcode cases pass with one expected iPad-only skip; all five actual Android startup-theme cases pass.
• Audio-overlay compatibility passes 533 host tests with one mechanical test-constructor adjustment. Fresh independent review found no defects.