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>

tools/setup.sh

@@ -11,6 +11,7 @@ GODOT_BIN_DIR=".godot-bin"
 GODOT_BIN="${GODOT_BIN_DIR}/godot"
 GUT_VERSION="v9.6.0" # v9.6.1+ reference AccessibilityServer, absent de Godot 4.6.3
 GDTOOLKIT_VERSION="4.5.0"
+PYRIGHT_VERSION="1.1.407"
 
 mkdir -p "${GODOT_BIN_DIR}"
 
@@ -46,6 +47,9 @@ if [ ! -d ".venv" ]; then
     python3 -m venv .venv
 fi
 ./.venv/bin/pip install --quiet --upgrade pip
-./.venv/bin/pip install --quiet "gdtoolkit==${GDTOOLKIT_VERSION}"
+./.venv/bin/pip install --quiet "gdtoolkit==${GDTOOLKIT_VERSION}" "pyright==${PYRIGHT_VERSION}"
 
-echo "Setup termine : Godot ${GODOT_VERSION}, GUT ${GUT_VERSION}, gdtoolkit ${GDTOOLKIT_VERSION}."
+echo "Import du projet (enregistre les class_name globaux : SchemaValidator, DataLoader...)."
+"${GODOT_BIN}" --headless --path . --import >/dev/null
+
+echo "Setup termine : Godot ${GODOT_VERSION}, GUT ${GUT_VERSION}, gdtoolkit ${GDTOOLKIT_VERSION}, pyright ${PYRIGHT_VERSION}."