feat(domain): add tasks/model.rs Task aggregate + Phase/Status/Priority VOs

[mpiton]

Summary

Implements Tasks bounded-context entity + value objects (task T-109). Unblocks T-110 (TaskRepository implementation), T-117 (TypeScript codegen), T-131 (architecture test). Phase state machine encodes ADR-013: agent halts at PR creation, leaving the final merge to humans.

Changes

• New domain/tasks/model.rs: Task aggregate (id, project_id, title, body, status, phase, priority, github_issue_id, created_at/updated_at with RFC3339 serde), three value objects: Phase enum (Backlog → Spec → Plan → Code → Qa → Pr → Done), Status enum (Pending/Running/Queued/Paused/Failed/Completed/Aborted), Priority enum (P0/P1/P2). Task::new(project_id, title) seeds fresh TaskId + Backlog phase + Pending status + all optional fields = None.
• New domain/shared/time.rs: now_utc() helper as single seam for wall-clock reads (enables future Clock port DI per ARCHI §4 without touching call sites).
• New domain/shared/test_support.rs: assert_send_sync() compile-time check (zero runtime cost, single source) + json_roundtrip(value, expected_json) helper collapsing 4-line serialize-then-deserialize boilerplate across all value-object tests.
• Updated domain/shared/mod.rs: exposed test_support module.
• Updated CHANGELOG.md: detailed Added entry for Task + Phase/Status/Priority, Changed entry explaining /simplify test consolidations (5 task_new_* tests → 1, 3 serde tests → 1, removed tautological value_objects_are_copy_eq_hash).

Testing

cargo test --workspace              # 99 tests pass (105→99 after consolidation)
cargo test -p forgent --lib domain  # domain tests only, 100% coverage
cargo clippy --workspace -- -D warnings
cargo fmt --check

All 10 domain/tasks/model.rs tests pass at 100% coverage (lines/regions/functions):

• task_new_seeds_documented_defaults
• two_new_tasks_get_different_ids
• phase_progresses_linearly_through_pipeline
• phase_done_has_no_successor
• value_objects_serde_use_pascal_case_variants
• task_serde_roundtrip_uses_rfc3339_timestamps
• task_with_optional_fields_set_serde_roundtrips
• value_objects_are_send_sync

(Plus 2 tests in shared/time.rs, 0 tests in shared/test_support.rs — it's compile-time helpers only.)

Related Issues

• Closes #T-109
• Refs T-110 (TaskRepository), T-117 (TypeScript codegen), T-131 (architecture test)

Notes for Reviewer

Architecture purity: No ts-rs in domain layer. TS bindings for Task come from interfaces-layer DTOs (T-117/T-118), keeping ARCHI §4.1 boundaries clean. Domain stays import-pure: only serde + time + uuid (architecture test still green).

Phase semantics: Phase::next() returns Option with Done → None per ADR-013 — agent creates PR but does not merge (merge is human action). Linear encoding (Backlog → Spec → ... → Pr → Done) is now type-level.

Clock port setup: Task::new calls shared now_utc() rather than OffsetDateTime::now_utc() inline. Future Clock port DI (ARCHI §4) can swap the implementation without touching call sites.

Test consolidation (from /simplify follow-up):

• 5 task_new_* tests merged into 1 task_new_seeds_documented_defaults (single Task::new covers 8 assertions)
• 3 Phase/Status/Priority_serde_roundtrip tests collapsed via new json_roundtrip helper
• Dropped value_objects_are_copy_eq_hash (runtime test of std's HashSet dedup; Copy/Eq/Hash are compile-time guaranteed by derive)

Shared helpers: assert_send_sync() and json_roundtrip() are new in test_support.rs; ids.rs and error.rs still have their own copies (refactoring those to use the shared version is T-132 follow-up, not in scope here).

Checklist

• Tests added (10 tests at 100% coverage, domain target ≥90%)
• Docs updated (CHANGELOG.md, module docs)
• No secrets, debug prints, or commented code
• Self-reviewed diff
• Architecture test green, clippy green, fmt green

Summary by CodeRabbit

• New Features

  • Introduces a Task model with workflow phases (Backlog → Done), execution statuses, priorities, timestamps, and a convenient task constructor for consistent seeding.

• Infrastructure

  • Safer persistence migrations with atomic execution and rollback behavior, plus improved migration idempotency.
  • Added shared time utility and test helpers to improve reliability of timing and serialization tests.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 96480a0f-f8c7-45c9-bd2e-3dc52c3710ed

📥 Commits

Reviewing files that changed from the base of the PR and between 93940ee and 1089d3f.

📒 Files selected for processing (1)

• CHANGELOG.md

✅ Files skipped from review due to trivial changes (1)

• CHANGELOG.md

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📝 Walkthrough

Walkthrough

Adds a Task domain model (value objects Phase/Status/Priority and Task entity with Task::new), a shared UTC time seam now_utc(), and test-only helpers (assert_send_sync, json_roundtrip) with accompanying unit tests and changelog entries.

Changes

Task Domain Model & Test Infrastructure

Layer / File(s)	Summary
Data Shape / Value Objects src-tauri/src/domain/tasks/model.rs	Introduces Phase, Status, Priority enums (serde) and Phase::next().
Time Seam src-tauri/src/domain/shared/time.rs	Adds pub fn now_utc() -> OffsetDateTime and tests for UTC offset and monotonicity.
Entity & Seeding src-tauri/src/domain/tasks/model.rs	Adds Task struct with RFC3339 timestamps and pub fn new(project_id, title) seeding defaults using now_utc().
Test Helpers src-tauri/src/domain/shared/test_support.rs, src-tauri/src/domain/shared/mod.rs	Adds test-only assert_send_sync<T: Send + Sync>(), json_roundtrip<T>(), and conditionally exposes pub mod test_support under #[cfg(test)].
Tests / Validation src-tauri/src/domain/tasks/model.rs (tests), src-tauri/src/domain/shared/time.rs (tests)	Unit tests cover Task defaults, distinct IDs, phase progression, serde roundtrips, RFC3339 timestamps, optional-field roundtrips, and Send/Sync assertions.
Changelog CHANGELOG.md	Documents added domain types, time seam, test helpers, and related persistence/migration notes.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

• mpiton/forgent#5: Implements scaffolding for the domain modules (shared/time.rs, shared/mod.rs, and tasks/model.rs) that this PR fills in.

Poem

🐰
A Backlog seed, a Phase that climbs,
Timestamps tied to UTC times.
Tests that whisper, "Send and Sync,"
JSON roundtrips—smooth as a wink.
Hopping onward, small changes fine.

🚥 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 clearly and concisely summarizes the main change: adding Task aggregate and Phase/Status/Priority value objects to the domain model, which aligns with the primary objective (T-109 Tasks bounded-context implementation).
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 unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/task-T-109-tasks-model

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[codspeed-hq]

Merging this PR will not alter performance

✅ 7 untouched benchmarks

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_{Comparing feat/task-T-109-tasks-model (1089d3f) with main (a5e1afd)}

[cubic-dev-ai]

1 issue found across 5 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="CHANGELOG.md">

<violation number="1" location="CHANGELOG.md:9">
P3: This changelog bullet accidentally appends the ids.rs change details after the tasks/model.rs summary (starting with "(`new`, `from_uuid`)…"). Trim the entry so it ends after the tasks/model.rs summary to avoid duplicated/misleading release notes.</violation>
</file>

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