refactor: extract dead_letter, archival, worker ops into diesel_common

[pratyush618]

Summary

• Extract all 4 dead_letter ops into impl_diesel_dead_letter_ops! macro (100% identical between SQLite/Postgres)
• Extract list_archived into impl_diesel_archival_ops! macro (archive_old_jobs stays backend-specific due to INSERT OR IGNORE vs ON CONFLICT DO NOTHING)
• Extract 6 of 7 worker ops into impl_diesel_worker_ops! macro (register_worker stays backend-specific due to replace_into vs on_conflict.do_update)

Eliminates ~250 LOC of duplication across 3 file pairs, extending the existing diesel_common/ macro pattern (jobs, locks, logs, metrics).

Test plan

• cargo test --workspace passes
• cargo check --workspace --features postgres compiles
• cargo clippy --workspace clean

Summary by CodeRabbit

• Refactor
  • Storage operations for job archival, dead-letter queue handling, and worker management now share unified implementations across database backends, reducing duplication and improving consistency.
• Tests
  • Added SQLite tests covering dead-letter retry error handling and removal of stale workers.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 38c18511-3f52-4551-a9a3-6d16283a5bbe

📥 Commits

Reviewing files that changed from the base of the PR and between 0162b5f and d86e050.

📒 Files selected for processing (3)

• crates/taskito-core/src/storage/diesel_common/dead_letter.rs
• crates/taskito-core/src/storage/diesel_common/workers.rs
• crates/taskito-core/src/storage/sqlite/tests.rs

🚧 Files skipped from review as they are similar to previous changes (2)

• crates/taskito-core/src/storage/diesel_common/dead_letter.rs
• crates/taskito-core/src/storage/diesel_common/workers.rs

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📝 Walkthrough

Walkthrough

Extracts duplicate Diesel database logic into three macros in diesel_common/ (archival, dead-letter, workers) and replaces explicit Postgres and SQLite implementations with macro invocations; adds SQLite tests for dead-letter retry-not-found and worker reaping.

Changes

Storage Macro Consolidation

Layer / File(s)	Summary
Shared Diesel macro implementations crates/taskito-core/src/storage/diesel_common/archival.rs, crates/taskito-core/src/storage/diesel_common/dead_letter.rs, crates/taskito-core/src/storage/diesel_common/workers.rs	Introduces impl_diesel_archival_ops!, impl_diesel_dead_letter_ops!, and impl_diesel_worker_ops! macros that implement paginated archived-job listing, transactional DLQ move/list/retry/purge, and worker heartbeat/status/list/reap/unregister/claim queries respectively; each macro is re-exported for crate use.
Module declarations and re-exports crates/taskito-core/src/storage/diesel_common/mod.rs	Adds archival, dead_letter, and workers submodules and re-exports the three macros for storage backends.
Postgres backend refactoring crates/taskito-core/src/storage/postgres/archival.rs, crates/taskito-core/src/storage/postgres/dead_letter.rs, crates/taskito-core/src/storage/postgres/workers.rs	Replaces explicit Postgres implementations for archival listing, dead-letter ops, and worker ops with impl_diesel_* macro invocations attached to PostgresStorage.
SQLite backend refactoring and tests crates/taskito-core/src/storage/sqlite/archival.rs, crates/taskito-core/src/storage/sqlite/dead_letter.rs, crates/taskito-core/src/storage/sqlite/workers.rs, crates/taskito-core/src/storage/sqlite/tests.rs	Replaces explicit SQLite implementations with the shared macros and adds tests asserting retry_dead returns QueueError::JobNotFound for missing IDs and that reap_dead_workers removes only stale workers.

🎯 3 (Moderate) | ⏱️ ~20 minutes

"🐰 I stitched three macros in a hop,
Postgres and SQLite now share the top.
Jobs archived, dead letters tried,
Workers reaped where heartbeats died —
Cleaner code, lighter hop!"

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: extracting dead_letter, archival, and worker operations into shared Diesel macros in diesel_common, which aligns with all modified files and the PR's core objective.
Docstring Coverage	✅ Passed	Docstring coverage is 80.00% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch refactor/diesel-common-expansion

---

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[coderabbitai]

Actionable comments posted: 2

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@crates/taskito-core/src/storage/diesel_common/dead_letter.rs`:
- Around line 82-87: The code in retry_dead currently maps every DB error from
dead_letter::table.find(...).first(&mut conn) to QueueError::JobNotFound and
later doesn't verify the delete actually removed a row, which causes races and
masks real DB errors; change the first() call to match the diesel error: if
Err(diesel::result::Error::NotFound) return
QueueError::JobNotFound(dead_id.to_string()), otherwise propagate or wrap other
diesel errors as a DB error (e.g., QueueError::Db or return Err(err.into())).
For the delete step (the diesel::delete(...).execute(&mut conn) call around
where DeadLetterRow is removed), check the returned affected rows count and if
it is 0 return QueueError::JobNotFound(dead_id.to_string()), and if execute
returns any other DB error propagate/wrap it instead of treating it as
not-found; apply the same pattern to the other similar block around lines
129-136.

In `@crates/taskito-core/src/storage/diesel_common/workers.rs`:
- Around line 53-60: The current logic selects dead_ids from workers::table and
then deletes rows by worker_id alone, which can remove workers that updated
their heartbeat after the select; change the delete to also require
last_heartbeat < cutoff so the removal only affects rows still stale (e.g., use
diesel::delete(workers::table.filter(workers::worker_id.eq_any(&dead_ids).and(workers::last_heartbeat.lt(cutoff))))
or equivalently include the last_heartbeat value with each selected id and
delete by matching both worker_id and that timestamp), keeping the symbols
workers::table, workers::worker_id, workers::last_heartbeat and the cutoff
variable referenced to ensure recovered workers are not deleted.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: f27fe902-0f1f-4b66-8efd-b084664b8d84

📥 Commits

Reviewing files that changed from the base of the PR and between b20ad9c and 0162b5f.

📒 Files selected for processing (10)

• crates/taskito-core/src/storage/diesel_common/archival.rs
• crates/taskito-core/src/storage/diesel_common/dead_letter.rs
• crates/taskito-core/src/storage/diesel_common/mod.rs
• crates/taskito-core/src/storage/diesel_common/workers.rs
• crates/taskito-core/src/storage/postgres/archival.rs
• crates/taskito-core/src/storage/postgres/dead_letter.rs
• crates/taskito-core/src/storage/postgres/workers.rs
• crates/taskito-core/src/storage/sqlite/archival.rs
• crates/taskito-core/src/storage/sqlite/dead_letter.rs
• crates/taskito-core/src/storage/sqlite/workers.rs