Add Wave contract schemas for pipeline validation

JSON Schema definitions for all pipeline handover contracts
including issue analysis, research, enhancement, and sync flows.

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

.wave/contracts/debug-hypotheses.schema.json

@@ -0,0 +1,22 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "type": "object",
+  "required": ["hypotheses"],
+  "properties": {
+    "hypotheses": {
+      "type": "array",
+      "minItems": 1,
+      "items": {
+        "type": "object",
+        "required": ["id", "description", "likelihood", "test_approach"],
+        "properties": {
+          "id": { "type": "integer" },
+          "description": { "type": "string", "minLength": 1 },
+          "likelihood": { "type": "string", "enum": ["high", "medium", "low"] },
+          "test_approach": { "type": "string", "minLength": 1 },
+          "expected_result_if_true": { "type": "string" }
+        }
+      }
+    }
+  }
+}