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.

out/mirror/thin/oci/index.json

@@ -3,8 +3,8 @@
   "manifests": [
     {
       "mediaType": "application/vnd.oci.image.manifest.v1+json",
-      "digest": "sha256:f6bd80fe9d346e7306c69832e29180346454005a0751c77ae2ebb7332be94642",
-      "size": 485,
+      "digest": "sha256:0074121d4adef7dc8181607645af330a475608b0d52909e0efd421508f14437d",
+      "size": 486,
       "annotations": {"org.opencontainers.image.ref.name": "mirror-thin-v1"}
     }
   ]

out/mirror/thin/oci/manifest.json

@@ -8,8 +8,8 @@
   "layers": [
     {
       "mediaType": "application/vnd.oci.image.layer.v1.tar+gzip",
-      "size": 830,
-      "digest": "sha256:1ef17d14c09e74703b88753d6c561d8c8a8809fe8e05972257adadfb91b71723",
+      "size": 2468,
+      "digest": "sha256:fb1ce26388a1f1ab2eb90aae6d63ac05de326fbbd947fbf7a17b980232c9fc7d",
       "annotations": {"org.stellaops.bundle.type": "mirror-thin-v1"}
     }
   ]