Fix loan valuation definition bypasses

docs/data-model.md

@@ -118,14 +118,14 @@
 
 ### transactions, import-batches, reconciliation-sessions, review-decisions, schema-meta — 기존 entities
 
-기존 필드와 관계를 보존한다. import는 거래를 기록할 수 있지만 balance valuation candidate는 dated `unverified` row만 추가한다. reconciliation은 calculated balance provenance와 `VALUATION_MANAGED` 상태를 보존하며 investment valuation 때문에 transaction을 생성하지 않는다. `schema_meta.schema_version`은 12다.
+기존 필드와 관계를 보존한다. import는 거래를 기록할 수 있지만 balance valuation candidate는 dated `unverified` row만 추가한다. loan cache writes without an explicit liability definition do not append an `account_valuations` candidate; current cache와 transaction import는 그대로 완료하며 정의를 추정하지 않는다. reconciliation은 calculated balance provenance와 `VALUATION_MANAGED` 상태를 보존하며 investment valuation 때문에 transaction을 생성하지 않는다. `schema_meta.schema_version`은 12다.
 
 ### 현재 계좌 잔액 캐시와 기준일
 
 - `last_balance` is the current cache value: it is the latest current balance observed by an import or account write, not a historical valuation and not opening evidence.
 - `last_balance_basis_date` is the basis field for the evidence represented by that cache. It is a date when known; legacy or date-less writes store unknown/NULL and must not be inferred from `last_synced_at` or a valuation row.
 - `last_synced_at` is the execution/sync timestamp: when the import or account write advanced the cache, not the evidence basis date.
-- imports and account writes advance the account cache; they may also append a dated `account_valuations` candidate, but updating the cache does not rewrite historical rows.
+- imports and account writes advance the account cache; non-loan writes may also append a dated `account_valuations` candidate. loan cache writes without an explicit liability definition do not append historical evidence, and updating the cache does not rewrite historical rows.
 - `account_valuations` is the historical authority. A dated valuation remains append-only evidence even when it is older than the current cache; older evidence never rolls back the current cache.
 
 ## 관계와 불변조건

docs/interface-contract.md

@@ -337,11 +337,11 @@ AppTest는 callback, query mapping, synthetic renderer output과 error/loading e
 
 The public contract explicitly supports these exact values: source_type: `manual`, `import`, `account_write`, `reconciliation`, `snapshot`; verification_status: `verified`, `unverified`, `rejected`; valuation_kind: `balance`, `cash_balance`, `total_value`, `loan`, `loan_balance`; representative_liability_definition: `principal_only`, `principal_interest_fees`. These are the currently supported enums, not a delegation to source code.
 
-loan accounts require representative_liability_definition for `loan`, `loan_balance`, and `balance` aliases. legacy valuation-kind aliases remain accepted and map to the canonical purpose; alias acceptance does not broaden the canonical enum set. Invalid values, missing loan definitions, and incompatible definitions return `validation_error` and perform no write. A validation failure returns `validation_error` and performs no write.
+loan accounts require representative_liability_definition for `loan`, `loan_balance`, and `balance` aliases. Those are the only accepted valuation kinds for loan accounts; `cash_balance` and `total_value` do not represent a loan liability and are rejected. legacy valuation-kind aliases remain accepted and map to the canonical purpose; alias acceptance does not broaden the canonical enum set. Invalid values, missing loan definitions, and incompatible definitions return `validation_error` and perform no write. A validation failure returns `validation_error` and performs no write.
 
 loan valuations map to liabilities and non-loan valuations map to assets. The output mapping preserves the existing envelopes and signatures: `success` remains the outcome field, failures include `error_code` and `error`, and validation or conflict failures do not partially write.
 
-Account current-cache writes keep `last_balance_basis_date` (optional `YYYY-MM-DD`) separate from `last_synced_at` (execution/sync timestamp). `create_ledger_account` keeps the established positional `db_path` argument and adds `last_balance_basis_date` after it as an optional keyword. `update_ledger_account` accepts the same field through its existing keyword-field boundary. A balance with no explicit basis advances only the current display cache, leaves the basis unknown, and creates no historical valuation candidate; an explicit balance+basis pair may advance the cache and append an unverified candidate. Older explicit evidence is retained as history and does not roll back a newer dated cache.
+Account current-cache writes keep `last_balance_basis_date` (optional `YYYY-MM-DD`) separate from `last_synced_at` (execution/sync timestamp). `create_ledger_account` keeps the established positional `db_path` argument and adds `last_balance_basis_date` after it as an optional keyword. `update_ledger_account` accepts the same field through its existing keyword-field boundary. A balance with no explicit basis advances only the current display cache, leaves the basis unknown, and creates no historical candidate. A dated older non-loan balance appends historical evidence but cannot roll back a newer current cache. loan cache writes without an explicit liability definition do not append a historical candidate; they preserve current-cache and import behavior without inferring a definition. Import and account writers use deterministic candidate keys.
 
 ### shared contract and adapter limits
 

docs/requirements/req-003_account-valuation-history.md

@@ -100,7 +100,7 @@ amount와 principal/interest/fee/cost_basis/net_contributed/profit은 exact inte
 
 ### REQ-003.05 — current와 historical authority
 
-current latest display와 historical authority를 분리한다. `last_balance`는 opening evidence가 아니라 external current comparison이며, balance_after/opening evidence가 모두 없으면 `INCOMPLETE_CALCULATION`이다. 늦게 도착한 historical row는 current를 과거로 되돌리지 않으며 cannot roll back newer current cache. account/import writes는 real dated evidence가 있을 때만 dated `unverified` candidate를 만든다.
+current latest display와 historical authority를 분리한다. `last_balance`는 opening evidence가 아니라 external current comparison이며, balance_after/opening evidence가 모두 없으면 `INCOMPLETE_CALCULATION`이다. 늦게 도착한 historical row는 current를 과거로 되돌리지 않으며 cannot roll back newer current cache. account/import writes는 real dated evidence가 있을 때만 dated `unverified` candidate를 만든다. 대출 cache write는 대표 부채 정의가 없으면 이력 후보를 추가하지 않는다. 이때 current cache와 import 처리는 유지하고 정의를 추정하지 않는다.
 
 **영향 범위**
 - 인터페이스: account update/import candidate, list/select/report