semi implemented and features implemented save checkpoint

docs/features/unchecked/cli/reachability-query-api-and-triage-flow.md

@@ -0,0 +1,25 @@
+# Reachability Query API and Triage Flow
+
+## Module
+Cli
+
+## Status
+IMPLEMENTED
+
+## Description
+CLI commands and policy engine services consume reachability facts to drive triage decisions (reachable/unreachable/unknown).
+
+## Implementation Details
+- **Command Group**: `src/Cli/StellaOps.Cli/Commands/ReachabilityCommandGroup.cs` -- reachability query commands
+- **ReachGraph Commands**: `src/Cli/StellaOps.Cli/Commands/ReachGraph/ReachGraphCommandGroup.cs` -- graph query operations
+- **Commands**:
+  - `stella reachability list --scan <id>` -- list reachability results
+  - `stella reachability explain <cve>` -- explain reachability determination
+  - `stella reachability query <cve> --digest <digest>` -- query reachability for specific CVE/artifact pair
+
+## E2E Test Plan
+- [ ] Run `stella reachability list --scan <id>` and verify reachability results (reachable/unreachable/unknown)
+- [ ] Run `stella reachability explain CVE-2024-1234` and verify explanation with call path evidence
+- [ ] Run `stella reachability query CVE-2024-1234 --digest sha256:abc123` and verify specific query
+- [ ] Verify triage decisions based on reachability status
+- [ ] Verify `--format json` output