Add JSON schemas, data validator, and first CE1 content

Introduces a generic JSON-Schema-subset validator in GDScript
(scripts/data/schema_validator.gd) used both by `make validate-data`
and, later, by ExerciseEngine at load time, plus semantic_checks.gd
for cross-field constraints a schema can't express (answer index
bounds, at least one faulty token in sentence correction, word count
matching between a dictation's target_text and its annotations).

Schemas cover rule, exercise (dispatched per type: multiple_choice,
sentence_correction), dictation, curriculum, and save (save.schema.json
is not yet wired into validate-data; saves live in user://, handled
at the Profiles/Saves step).

First draft content for the CE1 "accord_adjectif" rule (one rule, two
multiple-choice exercises, one sentence correction, one dictation,
one curriculum entry) exercises the full pipeline end to end and
seeds docs/review/content-review.md, regenerated by the new
tools/generate_content_review.py (`make content-review`).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

data/schemas/curriculum.schema.json

@@ -0,0 +1,24 @@
+{
+  "type": "object",
+  "required": [
+    "level",
+    "region_id",
+    "chapter_id",
+    "title",
+    "rule_ids",
+    "review_status"
+  ],
+  "additionalProperties": false,
+  "properties": {
+    "level": { "type": "string", "enum": ["CE1", "CE2"] },
+    "region_id": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" },
+    "chapter_id": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" },
+    "title": { "type": "string", "minLength": 1 },
+    "rule_ids": {
+      "type": "array",
+      "minItems": 1,
+      "items": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" }
+    },
+    "review_status": { "type": "string", "enum": ["draft", "validated"] }
+  }
+}

data/schemas/dictation.schema.json

@@ -0,0 +1,47 @@
+{
+  "type": "object",
+  "required": [
+    "id",
+    "level",
+    "domain",
+    "rule_ids",
+    "difficulty",
+    "target_text",
+    "words",
+    "audio_id",
+    "audio_provisional",
+    "accepted_variants",
+    "review_status"
+  ],
+  "additionalProperties": false,
+  "properties": {
+    "id": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" },
+    "level": { "type": "string", "enum": ["CE1", "CE2"] },
+    "domain": { "type": "string", "enum": ["grammaire", "orthographe"] },
+    "rule_ids": {
+      "type": "array",
+      "minItems": 1,
+      "items": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" }
+    },
+    "difficulty": { "type": "integer", "minimum": 1, "maximum": 3 },
+    "target_text": { "type": "string", "minLength": 1 },
+    "words": {
+      "type": "array",
+      "minItems": 1,
+      "items": {
+        "type": "object",
+        "required": ["text"],
+        "additionalProperties": false,
+        "properties": {
+          "text": { "type": "string", "minLength": 1 },
+          "rule_id": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" },
+          "expects_capital": { "type": "boolean" }
+        }
+      }
+    },
+    "audio_id": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" },
+    "audio_provisional": { "type": "boolean" },
+    "accepted_variants": { "type": "array", "items": { "type": "string" } },
+    "review_status": { "type": "string", "enum": ["draft", "validated"] }
+  }
+}

data/schemas/exercise_multiple_choice.schema.json

@@ -0,0 +1,43 @@
+{
+  "type": "object",
+  "required": [
+    "id",
+    "level",
+    "domain",
+    "skill",
+    "rule_id",
+    "difficulty",
+    "type",
+    "instruction",
+    "question",
+    "answers",
+    "correct_answer",
+    "hint",
+    "explanation",
+    "review_tags",
+    "review_status"
+  ],
+  "additionalProperties": false,
+  "properties": {
+    "id": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" },
+    "level": { "type": "string", "enum": ["CE1", "CE2"] },
+    "domain": { "type": "string", "enum": ["grammaire", "orthographe"] },
+    "skill": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" },
+    "rule_id": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" },
+    "difficulty": { "type": "integer", "minimum": 1, "maximum": 3 },
+    "type": { "type": "string", "const": "multiple_choice" },
+    "instruction": { "type": "string", "minLength": 1 },
+    "question": { "type": "string", "minLength": 1 },
+    "answers": {
+      "type": "array",
+      "minItems": 2,
+      "maxItems": 6,
+      "items": { "type": "string", "minLength": 1 }
+    },
+    "correct_answer": { "type": "integer", "minimum": 0 },
+    "hint": { "type": "string", "minLength": 1 },
+    "explanation": { "type": "string", "minLength": 1 },
+    "review_tags": { "type": "array", "items": { "type": "string" } },
+    "review_status": { "type": "string", "enum": ["draft", "validated"] }
+  }
+}

data/schemas/exercise_sentence_correction.schema.json

@@ -0,0 +1,48 @@
+{
+  "type": "object",
+  "required": [
+    "id",
+    "level",
+    "domain",
+    "skill",
+    "rule_id",
+    "difficulty",
+    "type",
+    "instruction",
+    "tokens",
+    "hint",
+    "explanation",
+    "review_tags",
+    "review_status"
+  ],
+  "additionalProperties": false,
+  "properties": {
+    "id": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" },
+    "level": { "type": "string", "enum": ["CE1", "CE2"] },
+    "domain": { "type": "string", "enum": ["grammaire", "orthographe"] },
+    "skill": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" },
+    "rule_id": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" },
+    "difficulty": { "type": "integer", "minimum": 1, "maximum": 3 },
+    "type": { "type": "string", "const": "sentence_correction" },
+    "instruction": { "type": "string", "minLength": 1 },
+    "tokens": {
+      "type": "array",
+      "minItems": 2,
+      "items": {
+        "type": "object",
+        "required": ["text", "correct"],
+        "additionalProperties": false,
+        "properties": {
+          "text": { "type": "string", "minLength": 1 },
+          "correct": { "type": "boolean" },
+          "expected": { "type": "string", "minLength": 1 },
+          "rule_id": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" }
+        }
+      }
+    },
+    "hint": { "type": "string", "minLength": 1 },
+    "explanation": { "type": "string", "minLength": 1 },
+    "review_tags": { "type": "array", "items": { "type": "string" } },
+    "review_status": { "type": "string", "enum": ["draft", "validated"] }
+  }
+}

data/schemas/rule.schema.json

@@ -0,0 +1,22 @@
+{
+  "type": "object",
+  "required": [
+    "rule_id",
+    "level",
+    "domain",
+    "skill",
+    "statement",
+    "example",
+    "review_status"
+  ],
+  "additionalProperties": false,
+  "properties": {
+    "rule_id": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" },
+    "level": { "type": "string", "enum": ["CE1", "CE2"] },
+    "domain": { "type": "string", "enum": ["grammaire", "orthographe"] },
+    "skill": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" },
+    "statement": { "type": "string", "minLength": 1 },
+    "example": { "type": "string", "minLength": 1 },
+    "review_status": { "type": "string", "enum": ["draft", "validated"] }
+  }
+}

data/schemas/save.schema.json

@@ -0,0 +1,32 @@
+{
+  "type": "object",
+  "required": [
+    "schema_version",
+    "profile_id",
+    "display_name",
+    "school_level",
+    "session_count",
+    "unlocked_regions",
+    "skills",
+    "rewards"
+  ],
+  "additionalProperties": false,
+  "properties": {
+    "schema_version": { "type": "integer", "minimum": 1 },
+    "profile_id": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" },
+    "display_name": { "type": "string", "minLength": 1 },
+    "school_level": { "type": "string", "enum": ["CE1", "CE2"] },
+    "session_count": { "type": "integer", "minimum": 0 },
+    "unlocked_regions": { "type": "array", "items": { "type": "string" } },
+    "skills": { "type": "object" },
+    "rewards": {
+      "type": "object",
+      "required": ["stars", "items"],
+      "additionalProperties": false,
+      "properties": {
+        "stars": { "type": "integer", "minimum": 0 },
+        "items": { "type": "array", "items": { "type": "string" } }
+      }
+    }
+  }
+}