[rd-code-23]

Problem

Routines may optionally be planned for recurring days and local times, but the persistence model did not yet have a schedule record. Scheduling must represent user intent without prematurely introducing time-zone conversion, notifications, or calendar infrastructure.

What changed

• Added the Drizzle routine_schedules table.
• Exported it from the complete database schema index.
• Generated migration 0005_freezing_siren.sql and its Drizzle metadata.
• Finalized and documented the day-of-week convention in docs/database.md.
• Added concise field comments and explicit routine-deletion behavior.

Table design

Each schedule record contains:

• generated UUID identifier
• required parent routine
• day of week
• user-local planned time
• created and updated timestamps

The day convention is Sunday 0 through Saturday 6, matching JavaScript's Date#getDay() convention. PostgreSQL enforces the allowed 0–6 range.

local_time uses TIME(0) without a time-zone offset because it represents recurring local intent, such as Monday at 6:00 PM, rather than an absolute moment. Time-zone storage and notification conversion remain intentionally out of scope.

Integrity and deletion behavior

A unique (routine_id, day_of_week, local_time) index rejects duplicate schedule entries and supports loading schedules by routine through its leading routine column.

Deleting a routine cascades to its schedule entries because those entries have no meaning without their parent routine.

Scope

This PR implements only #60. It does not add notifications, user time zones, one-off calendar dates, schedule endpoints, routine UI, or dashboard integration.

Migration verification

Drizzle detected six tables and the expected schedule shape: six columns, one index, and one foreign key. A second generation reported No schema changes, nothing to migrate.

Verification

• pnpm --filter @goforlift/api typecheck
• pnpm --filter @goforlift/api test — 48 tests passed
• pnpm --filter @goforlift/api lint
• Prettier checks for changed schema, metadata, and documentation
• git diff --check

The migration is committed but was not applied to a developer's local PostgreSQL database as part of this PR.

Closes #60