metaagent session-005: METASTATE + HANDOFF

- All 7 tasks archived (T1-T7 in .agent/archive/tasks/)
- All 7 requests approved and moved to .agent/archive/requests/
- .agent/archive/index.json created
- .agent/context/project-state.md updated (post-refactor snapshot)
- .agent/handoff-summary.md (full summary for next agent)
- .agent/session-summary.md (phase-level summary)
- .agent/roadmap/sources.md (updated priorities)
- .agent/checkpoints.json: handoff=completed

All 8 phases completed: INIT, ANALYSE, ROADMAP, DECOMPOSITION,
EXECUTION, METASTATE, HANDOFF (DESIGN skipped for existing project).

.agent/archive/requests/req-T2.json

@@ -0,0 +1,34 @@
+{
+  "request_id": "req-T2",
+  "task_id": "T2",
+  "title": "Pydantic v2 — replace @dataclass with BaseModel",
+  "status": "ready_for_review",
+  "goal": "Заменить ручную сериализацию на pydantic.BaseModel, добавить валидацию",
+  "changes": {
+    "summary": "Все 7 моделей domain/ переведены с @dataclass на pydantic.BaseModel. Удалены ручные to_dict()/from_dict() — заменены на model_dump(mode='json')/model_validate(). Добавлены field_validators: Account.balance >= 0, Transaction.amount != 0, RecurringCashflow.amount != 0 и frequency ∈ {daily,weekly,monthly,yearly}, Liability.interest/payment >= 0, ExchangeRate.rate > 0, ForecastScenario.multipliers >= 0. UUID в JSON автоматически сериализуется как str. excel_sync.py адаптирован на model_validate(). Тесты test_model.py и test_currency.py обновлены. pyproject.toml: pydantic>=2.0.",
+    "commits": ["c765f36"],
+    "files_changed": [
+      "domain/account.py, asset.py, currency.py, liability.py, recurring.py, scenario.py, transaction.py, model.py",
+      "infrastructure/sync/excel_sync.py",
+      "tests/test_model.py, tests/test_currency.py",
+      "pyproject.toml"
+    ]
+  },
+  "verification": {
+    "tests_passed": "63/63",
+    "validators_work": "Account negative balance, Transaction zero amount, ExchangeRate negative rate — all rejected",
+    "uuid_in_json_as_str": true,
+    "round_trip": "ok",
+    "cf_init_works": true,
+    "cf_forecast_works": true,
+    "cf_scenario_works": true
+  },
+  "fulfills_ac": [
+    "Все модели domain/ — наследники pydantic.BaseModel",
+    "Удалены ручные to_dict() и from_dict()",
+    "UUID в JSON сериализуется как строка",
+    "Валидация работает (balance, amount, rate, frequency)",
+    "Excel-sync адаптирован под pydantic",
+    "pytest 63/63"
+  ]
+}