Add legacy rollout migration to paginated history (#37175)

## What changed

- Add `LocalThreadStore::migrate_rollouts` with dry-run and apply modes,
  optional thread selection, throughput limiting, and per-rollout outcomes.
- Canonicalize legacy JSONL records into paginated history while preserving
  model-visible conversation context, including compressed rollouts and copied
  fork history.
- Publish replacements atomically and journal migrations so interrupted SQLite
  projections can be recovered. Coordinate migration with rollout compression
  and skip rollouts with active writers.
- Make paginated history a one-way SQLite promotion so stale metadata cannot
  downgrade a migrated thread.

## Testing

- Cover legacy record normalization, dry runs, idempotency, malformed input,
  compressed rollouts, active writers, interrupted migration recovery, and a
  cold app-server resume after migration.

GitOrigin-RevId: b9991b659f28ebb52da39ce62e8b4e0bae2ba2bb

codex-rs/thread-store/Cargo.toml

@@ -23,6 +23,7 @@ codex-rollout = { workspace = true }
 codex-state = { workspace = true }
 codex-utils-absolute-path = { workspace = true }
 codex-utils-path = { workspace = true }
+codex-utils-path-uri = { workspace = true }
 futures = { workspace = true }
 pulldown-cmark = { workspace = true }
 serde = { workspace = true, features = ["derive"] }
@@ -31,6 +32,7 @@ sqlx = { workspace = true }
 thiserror = { workspace = true }
 tokio = { workspace = true }
 tracing = { workspace = true }
+zstd = { workspace = true }
 
 [dev-dependencies]
 codex-utils-absolute-path = { workspace = true }
@@ -38,4 +40,3 @@ pretty_assertions = { workspace = true }
 tempfile = { workspace = true }
 tokio = { workspace = true, features = ["macros", "rt-multi-thread"] }
 uuid = { workspace = true }
-zstd = { workspace = true }