diff --git a/docs/00-governance/CLEANUP_LOG.md b/docs/00-governance/CLEANUP_LOG.md
index f73259e..3dcc154 100644
--- a/docs/00-governance/CLEANUP_LOG.md
+++ b/docs/00-governance/CLEANUP_LOG.md
@@ -21,3 +21,145 @@
 - Added a softer revision note to `README.md` instead of a historical warning.
 - Marked `docs/INDEX.md` historical in place because it currently misdirects navigation.
 - Added follow-up debt: shared metrics vocabulary currently duplicated in `docs/02-runbooks/backtest_review_workflow.md` and `docs/02-runbooks/live_test_review_workflow.md`; later extract to shared governance doc `docs/00-governance/metrics_vocabulary.md`.
+
+
+## Legacy Source Cleanup — Pass 1 (Non-Destructive)
+
+**Date:** 2026-04-05
+**Branch:** cleanup/legacy-source
+**Type:** Non-destructive archive + tombstone cleanup
+
+### Summary
+Performed a conservative source cleanup to reduce ambiguity for AI agents and developers.
+Focused on isolating legacy code paths and removing confirmed placeholder/tombstone artifacts without impacting the active runtime path.
+
+---
+
+### Actions Taken
+
+#### 1. Legacy Orders System Archived
+The `NT8.Core.Orders` namespace was explicitly marked as archived and superseded by `NT8.Core.OMS`.
+
+Moved to:
+- `src/_archive/legacy-orders/`
+  - `IOrderManager.cs`
+  - `OrderManager.cs`
+  - `OrderModels.cs`
+
+Paired test moved with source:
+- `tests/_archive/legacy-orders/OrderManagerTests.cs`
+
+Rationale:
+- Prevents compile/runtime confusion between legacy Orders and active OMS
+- Prevents tests from referencing removed implementation paths
+- Ensures AI agents do not target deprecated order management logic
+
+---
+
+#### 2. Placeholder Source Files Archived
+Moved to:
+- `src/_archive/placeholders/`
+  - `PlaceholderAdapter.cs`
+  - `PlaceholderContract.cs`
+  - `PlaceholderStrategy.cs`
+
+Rationale:
+- These files contain no meaningful implementation
+- They create false signal for AI-assisted development
+
+---
+
+#### 3. Placeholder Test Files Archived
+Moved to:
+- `tests/_archive/placeholders/`
+  - `Integration_PlaceholderTests.cs`
+  - `Performance_PlaceholderTests.cs`
+
+Deleted:
+- `tests/NT8.Integration.Tests/UnitTest1.cs`
+- `tests/NT8.Performance.Tests/UnitTest1.cs`
+
+Rationale:
+- Placeholder tests (`Assert.IsTrue(true)`) provide no coverage
+- They distort test signal and can mislead analysis workflows
+
+---
+
+#### 4. Tombstone / Dead Files Removed
+Deleted (confirmed comment-only or empty artifacts):
+- `src/NT8.Adapters/Class1.cs.bak`
+- `src/NT8.Contracts/Class1.cs`
+- `src/NT8.Strategies/Class1.cs`
+
+Rationale:
+- Files contained no executable logic
+- Safe removal reduces noise and ambiguity
+
+---
+
+### Deferred / Blocked Items
+
+These files were intentionally **not modified** in this pass due to active references or ambiguity:
+
+- `src/NT8.Adapters/Wrappers/BaseNT8StrategyWrapper.cs`
+- `src/NT8.Adapters/Wrappers/SimpleORBNT8Wrapper.cs`
+- `src/NT8.Core/Risk/RiskManager.cs`
+- `src/NT8.Adapters/NinjaTrader/NT8Adapter.cs`
+- `src/NT8.Core/Class1.cs.bak` (contains real code, not a tombstone)
+
+Status:
+- Blocked pending second cleanup pass
+
+Reason:
+- Wrapper layer has test dependencies that must be migrated or rewritten before archiving
+- Some files contain real logic and require classification (active vs legacy) before removal
+
+---
+
+### Verification
+
+- `verify-build.bat`: **PASS**
+- All tests passing:
+  - Core: 393/393
+  - Integration: 78/78
+  - Performance: 10/10
+
+No compile errors or regressions introduced.
+
+---
+
+### Impact
+
+- Eliminated legacy order management ambiguity
+- Reduced AI hallucination risk in source selection
+- Removed non-functional placeholder code and tests
+- Preserved full build and test integrity
+
+---
+
+### Follow-Up Actions
+
+1. Second cleanup pass:
+   - Wrapper layer isolation or migration
+   - RiskManager classification
+   - NT8Adapter classification
+   - Resolve `Class1.cs.bak` ambiguity
+
+2. Metrics vocabulary extraction:
+   - Duplicate metrics definitions exist in:
+     - `backtest_review_workflow.md`
+     - `live_test_review_workflow.md`
+   - Planned extraction target:
+     - `docs/00-governance/metrics_vocabulary.md`
+
+3. Optional:
+   - Introduce `src/_archive/experimental/` if needed for future isolation
+
+---
+
+### Notes
+
+- No protected runtime paths were modified
+- No namespaces or interfaces were changed
+- No `.csproj` files were modified
+- All changes were reversible via archive structure