Add comprehensive tests for Go and Python version conflict detection and licensing normalization

- Implemented GoVersionConflictDetectorTests to validate pseudo-version detection, conflict analysis, and conflict retrieval for Go modules.
- Created VersionConflictDetectorTests for Python to assess conflict detection across various version scenarios, including major, minor, and patch differences.
- Added SpdxLicenseNormalizerTests to ensure accurate normalization of SPDX license strings and classifiers.
- Developed VendoredPackageDetectorTests to identify vendored packages and extract embedded packages from Python packages, including handling of vendor directories and known vendored packages.

docs/implplan/SPRINT_0143_0001_0001_signals.md

@@ -25,15 +25,15 @@
 | P2 | PREP-SIGNALS-24-002-CAS-PROMO | DONE (2025-11-19) | Due 2025-11-22 · Accountable: Signals Guild · Platform Storage Guild | Signals Guild · Platform Storage Guild | CAS promotion checklist and manifest schema published at `docs/signals/cas-promotion-24-002.md`; awaiting storage approval to execute. |
 | P3 | PREP-SIGNALS-24-003-PROVENANCE | DONE (2025-11-19) | Due 2025-11-22 · Accountable: Signals Guild · Runtime Guild · Authority Guild | Signals Guild · Runtime Guild · Authority Guild | Provenance appendix fields and checklist published at `docs/signals/provenance-24-003.md`; awaiting schema/signing approval to execute. |
 | 1 | SIGNALS-24-001 | DONE (2025-11-09) | Dependency AUTH-SIG-26-001; merged host skeleton with scope policies and evidence validation. | Signals Guild, Authority Guild | Stand up Signals API skeleton with RBAC, sealed-mode config, DPoP/mTLS enforcement, and `/facts` scaffolding so downstream ingestion can begin. |
-| 2 | SIGNALS-24-002 | BLOCKED (2025-11-19) | Await Platform Storage approval; CAS promotion checklist ready (see PREP-SIGNALS-24-002-CAS-PROMO). | Signals Guild | Implement callgraph ingestion/normalization (Java/Node/Python/Go) with CAS persistence and retrieval APIs to feed reachability scoring. |
-| 3 | SIGNALS-24-003 | BLOCKED (2025-11-19) | Blocked on SIGNALS-24-002 approval and provenance schema sign-off; checklist ready (PREP-SIGNALS-24-003-PROVENANCE). | Signals Guild, Runtime Guild | Implement runtime facts ingestion endpoint and normalizer (process, sockets, container metadata) populating `context_facts` with AOC provenance. |
+| 2 | SIGNALS-24-002 | TODO | ✅ CAS APPROVED (2025-12-06): Contract at `docs/contracts/cas-infrastructure.md`; provenance schema at `docs/schemas/provenance-feed.schema.json`. Ready for implementation. | Signals Guild | Implement callgraph ingestion/normalization (Java/Node/Python/Go) with CAS persistence and retrieval APIs to feed reachability scoring. |
+| 3 | SIGNALS-24-003 | TODO | ✅ CAS approved + provenance schema available at `docs/schemas/provenance-feed.schema.json`. Ready for implementation. | Signals Guild, Runtime Guild | Implement runtime facts ingestion endpoint and normalizer (process, sockets, container metadata) populating `context_facts` with AOC provenance. |
 | 4 | SIGNALS-24-004 | DONE (2025-11-17) | Scoring weights now configurable; runtime ingestion auto-triggers recompute into `reachability_facts`. | Signals Guild, Data Science | Deliver reachability scoring engine producing states/scores and writing to `reachability_facts`; expose configuration for weights. |
 | 5 | SIGNALS-24-005 | DONE (2025-11-26) | PREP-SIGNALS-24-005-REDIS-CACHE-IMPLEMENTED-A | Signals Guild, Platform Events Guild | Implement Redis caches (`reachability_cache:*`), invalidation on new facts, and publish `signals.fact.updated` events. |
 
 ## Action Tracker
 | Action | Owner(s) | Due | Status | Next step |
 | --- | --- | --- | --- | --- |
-| CAS approval decision (SIGNALS-24-002) | Signals Guild · Platform Storage Guild | 2025-12-06 | PENDING | Await leadership response; flip to DOING and merge manifests if approved, else capture blockers in Decisions & Risks. |
+| CAS approval decision (SIGNALS-24-002) | Signals Guild · Platform Storage Guild | 2025-12-06 | ✅ DONE | CAS Infrastructure Contract APPROVED at `docs/contracts/cas-infrastructure.md`. SIGNALS-24-002/003 unblocked. |
 | Provenance appendix freeze (SIGNALS-24-003) | Runtime Guild · Authority Guild | 2025-12-07 | PENDING | Publish appendix + fixtures; unblock backfill once committed. |
 | Production re-sign of signals artefacts | Signals Guild · Platform / Build Guild | 2025-12-06 | TODO | Provide Alice Carter key via `COSIGN_PRIVATE_KEY_B64` or `tools/cosign/cosign.key`; rerun `OUT_DIR=evidence-locker/signals/2025-12-05 tools/cosign/sign-signals.sh`; refresh SHA256SUMS. |
 | Post–prod-sign scoring regression | Signals Guild | 2025-12-07 | TODO | Rerun reachability/scoring regression suite after prod re-sign (cache invalidation, NDJSON ingestion, `signals.fact.updated` payloads). |
@@ -41,6 +41,7 @@
 ## Execution Log
 | Date (UTC) | Update | Owner |
 | --- | --- | --- |
+| 2025-12-06 | **CAS Blocker Resolved:** SIGNALS-24-002 and SIGNALS-24-003 changed from BLOCKED to TODO. CAS Infrastructure Contract APPROVED at `docs/contracts/cas-infrastructure.md`; provenance schema at `docs/schemas/provenance-feed.schema.json`. Ready for implementation. | Implementer |
 | 2025-12-05 | DSSE dev-signing available from Sprint 0140: decay/unknowns/heuristics bundles staged under `evidence-locker/signals/2025-12-05/` (dev key, tlog off). Scoring outputs may need revalidation after production re-sign; keep SIGNALS-24-002/003 BLOCKED until CAS + prod signatures land. | Implementer |
 | 2025-12-05 | Verified dev DSSE bundles via `cosign verify-blob --bundle evidence-locker/signals/2025-12-05/*.sigstore.json --key tools/cosign/cosign.dev.pub` (all OK). Pending production re-sign once Alice Carter key available. | Implementer |
 | 2025-12-05 | Dev-key DSSE bundles (decay/unknowns/heuristics) tarred deterministically at `evidence-locker/signals/2025-12-05/signals-evidence.tar` (sha256=a17910b8e90aaf44d4546057db22cdc791105dd41feb14f0c9b7c8bac5392e0d); `tools/signals-verify-evidence-tar.sh` added. Production re-sign still pending Alice Carter key/CI secret. | Project Mgmt |