feat(deltalite): per-phase timings in UpsertStats

[Gilbert09]

Problem

delta-rs's merge().execute() returned a timing breakdown (scan / rewrite / execute). deltalite only measured the total upsert duration (for its deltalite_upsert_duration_seconds histogram) and returned no timing in UpsertStats. Follow-up to #75959, which restored structured stats logging on the warehouse side but has no phase timings to log.

Changes

Add three per-phase wall-clock timings (ms) to UpsertStats, measured in upsert_inner and exposed through the pyo3 getters:

• plan_ms — listing each touched partition's files + pruning which to rewrite.
• rewrite_ms — the parallel partition rewrites (reading + probing targets, writing new files) — the bulk.
• commit_ms — committing the new file set to the Delta log.

Also added to the "upsert committed" info! line. Bumps 0.1.2 → 0.1.3 (Cargo.toml + pyproject.toml + Cargo.lock); the README's UpsertStats field list is updated.

Testing

cargo check -p deltalite-core -p deltalite-python is clean (0 errors). The ci-deltalite-python build + differential parity suite runs on this PR.

After merge

build-deltalite publishes the 0.1.3 wheel and auto-pins it in the app. Because #75959's write log enumerates the UpsertStats getters generically, plan_ms / rewrite_ms / commit_ms will start appearing in the deltalite write: committed logs automatically once the pin lands — no further app change.

[trunk-io]

😎 This pull request was merged.

[github-actions]

🤖 CI report

✅ Playwright — all passed

All tests passed.

View test results →

❌ Hobby preview — Health check did not pass within 35 minutes

Failing fast because: Health check did not pass within 35 minutes

---

_{Run 30637659718 | Consecutive failures: 2}

⚠️ deltalite — version bump needed

It looks like the code of deltalite changed in this PR, but its version stayed the same at 0.1.3. 👀
Bump the version in rust/deltalite/python/Cargo.toml AND rust/deltalite/python/pyproject.toml (the two must match) before merging.

[deployment-status-posthog]

Deploy status

Environment	Status	Deployed At	Workflow
dev	✅ Deployed	2026-07-31 15:16 UTC	Run
prod-us	✅ Deployed	2026-07-31 15:35 UTC	Run
prod-eu	✅ Deployed	2026-07-31 15:35 UTC	Run

[Gilbert09]

Status update after bringing this branch up to date with master:

• All required status checks are green (Rust, Django, Node.js, Frontend, Playwright, Docker build, Semgrep, shellcheck, etc.).
• The one red check, Setup DO Hobby Instance and test, is not a required check and is failing on a pre-existing infra flake, not on anything in this PR. The droplet replays the full migration history from an empty DB on boot; that now runs past the job's 35-minute health-check window (Postgres migrations were still applying at ~34 min in), so the smoke test times out before the app serves /_health. This PR contains no migrations or app code — only the Rust deltalite change plus the deltalite dependency pin, which is what pulls uv.lock into the hobby path filter and triggers the run. Re-ran it once; it timed out the same way. The deltalite parity suite and the Rust build/tests all pass.
• The deltalite version-bump reminder in the CI report is a benign false positive: 0.1.3 is already published to PyPI and pinned here (0.1.2 → 0.1.3), and the required "Check version legitimacy" job passes. The reminder re-appears only because the workflow self-publishes during PR CI and then re-observes its own published version on the next push.

_{🦉 via talyn.dev}