Split administrative-correction into typed development/remission corrections

Resolves the WP-0003-T06 review flag: the single administrative-correction
ledger entry type had an unstated fold-side effect (concept §17 names the
type but never says which side of the target it corrects). Maintainer chose
option (a) — split into administrative-correction-development and
administrative-correction-remission so the corrected side is explicit in
the type name rather than an implicit library default.

- schemas/ledger_entry.schema.json: enum split, no other behavior change.
- src/target_revenue/fold.py: each new type maps to its named side only.
- specs/TargetLedgerSpecification.md, TechnicalSpecificationDocument.md
  §3.2, ProductRequirementsDocument.md FR-5: updated to the split types.
- tests/test_ledger_fold.py: dedicated coverage for both new types plus a
  regression test that the old unsplit type name is now rejected.

spec/TargetRevenueLicenseConcept.md §17 is left unedited — its entry-type
list is explicitly non-exhaustive ("may include"), so this specializes
rather than contradicts it.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

tests/test_ledger_fold.py

@@ -131,3 +131,81 @@ def test_remission_correction_can_reduce_over_remission():
     result = fold.fold_outstanding_target(100000, entries)
     assert result.remission_credit == 15000
     assert result.outstanding_target == 85000
+
+
+def test_administrative_correction_development_adjusts_development_side():
+    entries = [
+        {
+            "id": "trsl:entry:t0001",
+            "phase": "trsl:phase:t",
+            "type": "administrative-correction-development",
+            "amount": 3000,
+            "currency": "USD",
+            "recognized_at": "2026-01-01T00:00:00Z",
+            "evidence_reference": "confidential:evidence:t0001-admin",
+            "previous_entry_hash": "GENESIS",
+        },
+    ]
+    result = fold.fold_outstanding_target(100000, entries)
+    assert result.development_credit == 3000
+    assert result.remission_credit == 0
+    assert result.outstanding_target == 97000
+
+
+def test_administrative_correction_remission_adjusts_remission_side():
+    entries = [
+        {
+            "id": "trsl:entry:t0001",
+            "phase": "trsl:phase:t",
+            "type": "administrative-correction-remission",
+            "amount": 3000,
+            "currency": "USD",
+            "recognized_at": "2026-01-01T00:00:00Z",
+            "evidence_reference": "confidential:evidence:t0001-admin",
+            "previous_entry_hash": "GENESIS",
+        },
+    ]
+    result = fold.fold_outstanding_target(100000, entries)
+    assert result.development_credit == 0
+    assert result.remission_credit == 3000
+    assert result.outstanding_target == 97000
+
+
+def test_administrative_correction_types_are_schema_valid():
+    from target_revenue import validation
+
+    for entry_type in (
+        "administrative-correction-development",
+        "administrative-correction-remission",
+    ):
+        entry = {
+            "id": "trsl:entry:t0001",
+            "phase": "trsl:phase:t",
+            "type": entry_type,
+            "amount": 100,
+            "currency": "USD",
+            "recognized_at": "2026-01-01T00:00:00Z",
+            "evidence_reference": "confidential:evidence:t0001",
+            "previous_entry_hash": "GENESIS",
+        }
+        validation.validate_ledger_entry(entry)
+
+
+def test_old_unsplit_administrative_correction_type_is_no_longer_valid():
+    """The single ambiguous administrative-correction type was split
+    2026-07-29 (specs/TargetLedgerSpecification.md §2); it must no longer
+    validate as a known type."""
+    from target_revenue import validation
+
+    entry = {
+        "id": "trsl:entry:t0001",
+        "phase": "trsl:phase:t",
+        "type": "administrative-correction",
+        "amount": 100,
+        "currency": "USD",
+        "recognized_at": "2026-01-01T00:00:00Z",
+        "evidence_reference": "confidential:evidence:t0001",
+        "previous_entry_hash": "GENESIS",
+    }
+    with pytest.raises(validation.ConformanceError):
+        validation.validate_ledger_entry(entry)