feat(scanner): Complete PoE implementation with Windows compatibility fix

- Fix namespace conflicts (Subgraph → PoESubgraph)
- Add hash sanitization for Windows filesystem (colon → underscore)
- Update all test mocks to use It.IsAny<>()
- Add direct orchestrator unit tests
- All 8 PoE tests now passing (100% success rate)
- Complete SPRINT_3500_0001_0001 documentation

Fixes compilation errors and Windows filesystem compatibility issues.
Tests: 8/8 passing
Files: 8 modified, 1 new test, 1 completion report

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

docs2/architecture/overview.md

@@ -0,0 +1,38 @@
+# Architecture overview
+
+## System boundary
+- Self-hosted by default with optional licensing validation.
+- Offline-first, with all critical verification paths available without network access.
+
+## Core infrastructure
+- PostgreSQL: the only canonical database, with schema isolation per module.
+- Valkey: cache, queues, and streams (Redis compatible).
+- RustFS: object storage for content-addressed artifacts.
+- Optional: NATS JetStream as an alternative queue and stream transport.
+
+## External dependencies
+- OCI registry with referrers for SBOM and attestation discovery.
+- Fulcio or KMS-backed signing (optional, depending on crypto profile).
+- Rekor (optional) for transparency log anchoring.
+
+## Core services (high level)
+- Authority: OIDC and OAuth2 token issuance, DPoP and mTLS sender constraints.
+- Signer: DSSE signing with entitlement checks and scanner integrity verification.
+- Attestor: transparency logging and attestation verification.
+- Scanner (Web + Worker): SBOM generation, analyzers, inventory and usage views, diffs.
+- Concelier: advisory ingest under the Aggregation-Only Contract (AOC).
+- Excititor: VEX ingest under AOC with consensus and evidence preservation.
+- Policy Engine: deterministic policy evaluation with explain traces.
+- Scheduler: impact selection and analysis-only re-evaluation.
+- Notify: rules, channels, and delivery workflows.
+- Export Center: deterministic exports and offline bundles.
+- UI and CLI: operator and automation surfaces.
+- Zastava: runtime observer and optional admission enforcement.
+- Advisory AI: evidence-based guidance with guardrails.
+- Orchestrator: job DAGs and pack runs.
+
+## Trust boundaries
+- Authority issues short-lived OpTok tokens with sender constraints (DPoP or mTLS).
+- Signer enforces Proof of Entitlement (PoE) and scanner image integrity before signing.
+- Only Signer produces DSSE; only Attestor writes to Rekor.
+- All evidence is content-addressed and immutable once written.