feat: Add VEX compact fixture and implement offline verifier for Findings Ledger exports

- Introduced a new VEX compact fixture for testing purposes.
- Implemented `verify_export.py` script to validate Findings Ledger exports, ensuring deterministic ordering and applying redaction manifests.
- Added a lightweight stub `HarnessRunner` for unit tests to validate ledger hashing expectations.
- Documented tasks related to the Mirror Creator.
- Created models for entropy signals and implemented the `EntropyPenaltyCalculator` to compute penalties based on scanner outputs.
- Developed unit tests for `EntropyPenaltyCalculator` to ensure correct penalty calculations and handling of edge cases.
- Added tests for symbol ID normalization in the reachability scanner.
- Enhanced console status service with comprehensive unit tests for connection handling and error recovery.
- Included Cosign tool version 2.6.0 with checksums for various platforms.

src/Bench/StellaOps.Bench/Graph/ui_bench_plan.md

@@ -4,6 +4,7 @@ Purpose: provide a deterministic, headless flow for measuring graph UI interacti
 
 ## Scope
 - Use synthetic fixtures under `samples/graph/interim/` until canonical SAMPLES-GRAPH-24-003 lands.
+- Optional overlay layer (`overlay.ndjson`) is loaded when present and toggled during the run to capture render/merge overhead.
 - Drive a deterministic sequence of interactions:
   1) Load graph canvas with specified fixture.
   2) Pan to node `pkg-000001`.
@@ -11,7 +12,7 @@ Purpose: provide a deterministic, headless flow for measuring graph UI interacti
   4) Apply filter `name contains "package-0001"`.
   5) Select node, expand neighbors (depth 1), collapse.
   6) Toggle overlay layer (once available).
-- Capture timings: initial render, filter apply, expand/collapse, overlay toggle.
+- Capture timings: initial render, filter apply, expand/collapse, overlay toggle (when available).
 
 ## Determinism rules
 - Fixed seed for any randomized layouts (seed `424242`).