Add signal contracts for reachability, exploitability, trust, and unknown symbols

- Introduced `ReachabilityState`, `RuntimeHit`, `ExploitabilitySignal`, `ReachabilitySignal`, `SignalEnvelope`, `SignalType`, `TrustSignal`, and `UnknownSymbolSignal` records to define various signal types and their properties.
- Implemented JSON serialization attributes for proper data interchange.
- Created project files for the new signal contracts library and corresponding test projects.
- Added deterministic test fixtures for micro-interaction testing.
- Included cryptographic keys for secure operations with cosign.

docs/implplan/SPRINT_0165_0001_0001_timelineindexer.md

@@ -1,4 +1,4 @@
-# Sprint 0165-0001-0001 · Timeline Indexer (Export & Evidence 160.C)
+# Sprint 0165_0001_0001 · Timeline Indexer (Export & Evidence 160.C)
 
 ## Topic & Scope
 - Bootstrap Timeline Indexer service: migrations/RLS, ingestion, query APIs, and evidence linkage.
@@ -46,13 +46,12 @@
 | # | Action | Owner | Due (UTC) | Status |
 | --- | --- | --- | --- | --- |
 | 1 | Attach orchestrator/notification event schema sample to sprint doc. | Timeline Indexer Guild | 2025-12-02 | CLOSED (bound to `docs/events/scanner.event.*@1.json`) |
-| 2 | Obtain EvidenceLocker digest schema/sample manifest for linkage design. | Timeline Indexer Guild · Evidence Locker Guild | 2025-12-02 | OPEN |
+| 2 | Obtain EvidenceLocker digest schema/sample manifest for linkage design. | Timeline Indexer Guild · Evidence Locker Guild | 2025-12-06 | BLOCKED (await AdvisoryAI/Orch schema ETA sync 2025-12-06) |
 | 3 | Draft RLS/migration proposal and route to Security/Compliance for approval. | Timeline Indexer Guild | 2025-12-04 | CLOSED (RLS + audit sink implemented; ready for review) |
 
 ## Upcoming Checkpoints
-- Schema drop ETA for orchestrator/notification events (TBD).
-- EvidenceLocker digest schema publication (TBD).
-- Security/Compliance review for RLS proposal (TBD).
+- 2025-12-06 — Schema ETA sync (AdvisoryAI + Orchestrator/Notifications leads) to unblock evidence linkage; escalate to steering on 2025-12-07 if silent.
+- 2025-12-10 — Wave 160 snapshot refresh to align EvidenceLocker digest schema and ExportCenter handoff; extend to 2025-12-13 if still blocked.
 
 ## Decisions & Risks
 | Risk / Decision | Impact | Mitigation / Next step | Status |
@@ -66,7 +65,7 @@
 ### Risk table
 | Risk | Severity | Mitigation / Owner |
 | --- | --- | --- |
-| Orchestrator/notification schema slip. | High | Action 1 to secure sample; keep Wave 1 blocked until delivered. Owner: Timeline Indexer Guild. |
+| Orchestrator/notification schema slip. | Medium | Parser bound to `docs/events/*@1.json`; monitor 2025-12-06 ETA sync. Owner: Timeline Indexer Guild. |
 | EvidenceLocker digest schema slip. | High | Action 2 to obtain schema; block evidence linkage until received. Owner: Timeline Indexer Guild · Evidence Locker Guild. |
 | RLS review delayed. | Medium | Action 3 to draft and schedule review with Security/Compliance. Owner: Timeline Indexer Guild. |
 | Schema drift after migrations drafted. | Medium | Re-run schema diff against upstream docs before coding resumes. Owner: Timeline Indexer Guild. |
@@ -89,3 +88,4 @@
 | 2025-11-12 | Captured task snapshot and blockers; waiting on orchestrator/notifications schema and EvidenceLocker digest schema. | Planning |
 | 2025-11-19 | Normalized sprint to standard template and renamed from `SPRINT_165_timelineindexer.md` to `SPRINT_0165_0001_0001_timelineindexer.md`; content preserved. | Implementer |
 | 2025-11-19 | Added legacy-file redirect stub to prevent divergent updates. | Implementer |
+| 2025-12-04 | Synced checkpoints with Sprint 160: added 2025-12-06 schema ETA sync and 2025-12-10 refresh; updated Action 2 due date/status and risk severities. | Project PM |