docs(planning): clean up next milestone document and remove completion markers

- Remove excessive completion checkmarks and status markers throughout document
- Consolidate redundant sections on completed features
- Streamline executive summary and current status sections
- Focus content on upcoming quick wins and active tasks
- Remove duplicate phase completion listings
- Clean up success metrics and KPI sections
- Maintain essential planning information while reducing noise

docs/archive/swarm-network-endpoints-specification_completed_tasks.md

@@ -0,0 +1,21 @@
+# Archived Completed Tasks
+
+**Source File**: 07_backend/swarm-network-endpoints-specification.md
+**Archive Date**: 2026-03-08 12:35:30
+
+## Completed Tasks
+
+### (March 5, 2026)
+
+- **Category**: general
+- **Completion Date**: 2026-03-08
+- **Original Line**: 10
+- **Original Content**: - **Agent Network**: `/api/v1/agents/networks/*` endpoints - ✅ **IMPLEMENTED** (March 5, 2026)
+
+### (March 5, 2026)
+
+- **Category**: general
+- **Completion Date**: 2026-03-08
+- **Original Line**: 11
+- **Original Content**: - **Agent Receipt**: `/api/v1/agents/executions/{execution_id}/receipt` endpoint - ✅ **IMPLEMENTED** (March 5, 2026)
+