feat(reviews): independent per-user daily and weekly review toggles

[a-mandala]

Summary

• Extends the per-user review opt-out from PR feat(reviews): per-user review opt-out with /reviews command #110 into independent daily and weekly toggles, stored per tenant in SQLite (migration 0017 splits reviews_enabled into daily_enabled / weekly_enabled, seeded from the old combined value so existing opt-outs are preserved; absence of a row still defaults to ON for everyone).
• /reviews now shows both settings; /reviews daily on|off and /reviews weekly on|off toggle one; /reviews on|off remains a shorthand for both. On-demand /day_review / /week_review are unaffected.
• The daily delivery worker skips generation/delivery when the user's daily preference is off; the weekly worker does the same for the weekly preference. The global FROID_DAILY_REVIEW_DELIVERY_ENABLED / FROID_WEEK_REVIEW_WORKER_ENABLED env switches remain the master switches on top.

Testing

• New tests: repository persistence of each flag independently (defaults, read-back, re-enable, idempotency, no cross-effect); worker tests proving the daily worker skips when daily is off (no generation, no send) yet still delivers when only weekly is off, and the mirror for the weekly worker; adapter parsing tests for the new command forms (case-insensitive, usage fallback).
• Local CI-equivalent checks all green: cargo fmt --all --check, cargo check --locked --all-targets, cargo clippy --locked --all-targets -- -D warnings, cargo test --locked --all-targets (608 tests passing, 0 failed). Both commits compile individually.
• Not verified locally: real Telegram delivery end-to-end (no bot token/network in this environment) and migration 0017 against a production database with pre-existing opt-out rows (backfill logic covered only by review).