release: bump 0.6.6 -> 0.6.7 (#205)

Release 0.6.7 — ships the B12 DeMark indicators (474 total).

Version-string bump only: Cargo workspace + wickra-core dep, Python pyproject, Node package.json (+6 platform packages), both package-lock files, Cargo.lock, and CHANGELOG.

examples/node/package-lock.json

@@ -17,7 +17,7 @@
     },
     "../../bindings/node": {
       "name": "wickra",
-      "version": "0.6.6",
+      "version": "0.6.7",
       "license": "MIT OR Apache-2.0",
       "devDependencies": {
         "@napi-rs/cli": "^2.18.0"
@@ -26,12 +26,12 @@
         "node": ">= 18"
       },
       "optionalDependencies": {
-        "wickra-darwin-arm64": "0.6.6",
-        "wickra-darwin-x64": "0.6.6",
-        "wickra-linux-arm64-gnu": "0.6.6",
-        "wickra-linux-x64-gnu": "0.6.6",
-        "wickra-win32-arm64-msvc": "0.6.6",
-        "wickra-win32-x64-msvc": "0.6.6"
+        "wickra-darwin-arm64": "0.6.7",
+        "wickra-darwin-x64": "0.6.7",
+        "wickra-linux-arm64-gnu": "0.6.7",
+        "wickra-linux-x64-gnu": "0.6.7",
+        "wickra-win32-arm64-msvc": "0.6.7",
+        "wickra-win32-x64-msvc": "0.6.7"
       }
     },
     "node_modules/wickra": {