test: set minimum coverage thresholds to current levels (#486)

Statements: 55%, Branches: 47%, Functions: 48%, Lines: 54%.
Watermarks updated to [current, 80] to track progress toward goal.

Co-authored-by: github-manager <github-manager@example.com>
Co-authored-by: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>
Co-authored-by: Ricardo Cabral <me@ricardocabral.io>

Author: 4 people

.nycrc.json

@@ -1,26 +1,26 @@
 {
   "all": true,
   "cache": true,
-  "branches": 80,
-  "lines": 80,
-  "functions": 80,
-  "statements": 80,
+  "branches": 47,
+  "lines": 54,
+  "functions": 48,
+  "statements": 55,
   "watermarks": {
     "lines": [
-      80,
-      95
+      54,
+      80
     ],
     "functions": [
-      80,
-      95
+      48,
+      80
     ],
     "branches": [
-      80,
-      95
+      47,
+      80
     ],
     "statements": [
-      80,
-      95
+      55,
+      80
     ]
   },
   "extension": [