Étape 3 : import CSV/Excel des bénévoles et disponibilités

- Fichier unique, processus en deux temps : POST /editions/{id}/import/analyze
  (colonnes détectées, aperçu, mapping suggéré, demi-journées de l'édition)
  puis POST /editions/{id}/import/execute (mapping validé)
- Parser CSV (délimiteur et encodage devinés, BOM) et XLSX (openpyxl),
  détection XLSX par nombre magique
- Vocabulaire des valeurs de disponibilité (tri-état, accents/casse) et des
  tailles de t-shirt ; compétences créées à la volée dans le référentiel
- Rapport ligne par ligne : codes de traduction + paramètres, jamais de
  phrase. Doublons : upsert sur email, signalement sur (nom, prénom) sans
  email, doublons intra-fichier. Mode simulation (rollback, rien de persisté)
- 40 tests : parser, valeurs, service (tous les cas), endpoints
- Dépendances : python-multipart, openpyxl

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017uUsRg7XzopkCPWimwg9ZM

backend/uv.lock

@@ -53,8 +53,10 @@ source = { editable = "." }
 dependencies = [
     { name = "alembic" },
     { name = "fastapi" },
+    { name = "openpyxl" },
     { name = "psycopg", extra = ["binary"] },
     { name = "pydantic-settings" },
+    { name = "python-multipart" },
     { name = "sqlmodel" },
     { name = "uvicorn", extra = ["standard"] },
 ]
@@ -71,8 +73,10 @@ dev = [
 requires-dist = [
     { name = "alembic", specifier = ">=1.14" },
     { name = "fastapi", specifier = ">=0.115" },
+    { name = "openpyxl", specifier = ">=3.1" },
     { name = "psycopg", extras = ["binary"], specifier = ">=3.2" },
     { name = "pydantic-settings", specifier = ">=2.6" },
+    { name = "python-multipart", specifier = ">=0.0.12" },
     { name = "sqlmodel", specifier = ">=0.0.22" },
     { name = "uvicorn", extras = ["standard"], specifier = ">=0.32" },
 ]
@@ -136,6 +140,15 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/b1/5a/234e8fadf85c3cc48cb31c247b9e8e0c7f06ece80f5b29f9b8c241f9da4c/coverage-7.16.0-py3-none-any.whl", hash = "sha256:245f7de6d023a5bba375dbec9f2e0869bfa26ac0cc639bbb7b4c814884000b73", size = 214977 },
 ]
 
+[[package]]
+name = "et-xmlfile"
+version = "2.0.0"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/d3/38/af70d7ab1ae9d4da450eeec1fa3918940a5fafb9055e934af8d6eb0c2313/et_xmlfile-2.0.0.tar.gz", hash = "sha256:dab3f4764309081ce75662649be815c4c9081e88f0837825f90fd28317d4da54", size = 17234 }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/c1/8b/5fe2cc11fee489817272089c4203e679c63b570a5aaeb18d852ae3cbba6a/et_xmlfile-2.0.0-py3-none-any.whl", hash = "sha256:7a91720bc756843502c3b7504c77b8fe44217c85c537d85037f0f536151b2caa", size = 18059 },
+]
+
 [[package]]
 name = "fastapi"
 version = "0.141.1"
@@ -271,6 +284,18 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/e5/f1/216fc1bbfd74011693a4fd837e7026152e89c4bcf3e77b6692fba9923123/markupsafe-3.0.3-cp312-cp312-win_arm64.whl", hash = "sha256:35add3b638a5d900e807944a078b51922212fb3dedb01633a8defc4b01a3c85f", size = 13906 },
 ]
 
+[[package]]
+name = "openpyxl"
+version = "3.1.5"
+source = { registry = "https://pypi.org/simple" }
+dependencies = [
+    { name = "et-xmlfile" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/3d/f9/88d94a75de065ea32619465d2f77b29a0469500e99012523b91cc4141cd1/openpyxl-3.1.5.tar.gz", hash = "sha256:cf0e3cf56142039133628b5acffe8ef0c12bc902d2aadd3e0fe5878dc08d1050", size = 186464 }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/c0/da/977ded879c29cbd04de313843e76868e6e13408a94ed6b987245dc7c8506/openpyxl-3.1.5-py2.py3-none-any.whl", hash = "sha256:5282c12b107bffeef825f4617dc029afaf41d0ea60823bbb665ef3079dc79de2", size = 250910 },
+]
+
 [[package]]
 name = "packaging"
 version = "26.3"
@@ -436,6 +461,15 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/0d/17/c5c6b53ddc18f297992099b3d9ec16c855c0ccc83263a21fe4d1c625ec6c/python_dotenv-1.2.3-py3-none-any.whl", hash = "sha256:904552145e8bfed22162c09dab1c2b9b54fefa7b23ba780f4f26ca0316b0f0d9", size = 22780 },
 ]
 
+[[package]]
+name = "python-multipart"
+version = "0.0.32"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/5b/42/55c32bb9b12693c092ad250a0e82edb5b31ddeda6eb772de5f308b3804ad/python_multipart-0.0.32.tar.gz", hash = "sha256:be54b7f3fa167bb83e4fcd936b887b708f4e57fe75911c02aebf53efaf8d938e", size = 46881 }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/e1/04/e8135ebd1ad02c56ec633277529b2602ff99ff634be76cdba5744cf554fd/python_multipart-0.0.32-py3-none-any.whl", hash = "sha256:ff6d3f776f16878c894e52e107296ffc890e913c611b1a4ec6c44e2821fe2e23", size = 30042 },
+]
+
 [[package]]
 name = "pyyaml"
 version = "6.0.3"