refactor: preserve Daily Review on shared authorities

[Astro-Han]

Summary

Daily Review remains a first-class UI while its runtime uses shared authorities only:

• ScheduledTask owns schedule, timezone, catch-up, and Run now.
• Runtime Host ordinary Session / AgentRun / RuntimeEvent owns execution and recovery.
• ordinary Session + Markdown Artifact owns reports and history.

The dedicated scheduler, resident state, model path, archive store/dashboard, protocol, and IPC are removed. The shared usage and model-call ledgers are unchanged. Net diff: 1,384 lines deleted.

UI comparison

Before	After

Migration and compatibility

• Released file layouts (v0.1.0–v0.1.3) and SQLite layouts migrate idempotently.
• Existing deep reports become ordinary 7-day Session Artifacts; the retired deepEnabled schedule is not restored.
• Archives migrate even when the old model is unavailable, then their legacy source is consumed once. Unreadable files are preserved in place.
• Enabled config becomes the system preset task, or uses an existing runnable user Daily Review Agent task. Incompatible user tasks are left untouched and legacy config remains retryable.
• Reports appear only after an ordinary Session is terminal and has a live Markdown Artifact.
• Desktop bridge v2 gates the range-specific Run now prompt; Runtime Host compatibility epoch is 74.

Rollback after legacy retirement requires the pre-migration backup; migrated Sessions and Artifacts remain ordinary durable data.

Verification

• 158 focused Core, Storage, Runtime Host, UI, and Desktop tests
• affected workspace builds and typechecks
• Biome lint/format and git diff --check

Full-repository tests were not run.

AI use

• No generative tool made a substantive contribution
• Generative tooling made a substantive contribution

Codex implemented the migration, authority convergence, UX preservation, tests, and review fixes. Material commits carry Generated-by: Codex trailers.

Checklist

• Tests cover the change and fail without it
• Lint, format, typecheck and the affected suites pass locally

Does this PR entail a change in behavior?

• Yes — described above
• No

[Astro-Han]

Closing this draft because preserving the existing Daily Review contract would require rebuilding its range-bounded Session and Usage projection, fallback behavior, and legacy migration semantics on top of the shared runtime. That would defeat the simplification goal, so this implementation is not being proposed for merge.