feat: engine-state normalizer profile + sort_array_elements rule (#10)

- Rules.SortArrayElements: sort JSON arrays lexicographically (post-mask_guids order-independence)
- Normalizer output: UnsafeRelaxedJsonEscaping to preserve <GUID>/<TS>/<VOLATILE> tokens
- profiles/engine-state.yaml: normalize_paths + mask_guids + sort_array_elements + round_floats(2dp) + sort_json_keys
- RunnerOptions.SidecarProfile: default "engine-state", overridable via --sidecar-profile
- TestRunner.CaptureAndDiffSidecar: uses SidecarProfile instead of main Profile
- 4 new normalizer tests (136 total)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/Recordingtest.Normalizer/profiles/engine-state.yaml

@@ -0,0 +1,16 @@
+name: engine-state
+# Sidecar JSON profile: {"scene":{...}, "camera":{...}, "selection":{...}}
+#
+# Rules applied in order:
+#   1. normalize_paths  — mask document_path (user/temp dirs)
+#   2. mask_guids       — selected_ids GUIDs → <GUID> (order becomes irrelevant)
+#   3. sort_array_elements — sort selected_ids after masking
+#   4. round_floats     — camera eye/target/up coords with 2 decimal places
+#   5. sort_json_keys   — deterministic key order for clean diff
+float_decimals: 2
+rules:
+  - normalize_paths
+  - mask_guids
+  - sort_array_elements
+  - round_floats
+  - sort_json_keys