diff --git a/migrations/Version20260527164000.php b/migrations/Version20260527164000.php
new file mode 100644
index 0000000..477588c
--- /dev/null
+++ b/migrations/Version20260527164000.php
@@ -0,0 +1,90 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+/**
+ * M0 — Catalog : creation des tables `category_type` (referentiel) et `category`.
+ *
+ * Le referentiel `category_type` est cree vide ; ses valeurs seront seedees
+ * ulterieurement (cf. spec-back M0 § 9 HP-1).
+ *
+ * Index unique partiel sur (LOWER(name), category_type_id) WHERE deleted_at
+ * IS NULL : permet la recreation d'une categorie apres suppression logique
+ * (cf. RG-1.07). Postgres supporte nativement le `CREATE UNIQUE INDEX ... WHERE`.
+ *
+ * Les 4 colonnes Timestampable/Blamable (`created_at`, `updated_at`,
+ * `created_by`, `updated_by`) materialisent le pattern Shared (cf. ERP-52,
+ * spec-back M0 § 2.8) : NOT NULL pour les dates (remplies par le subscriber),
+ * nullable + ON DELETE SET NULL pour les FK user (creation hors contexte HTTP
+ * et suppression d'un user sans bloquer les categories existantes).
+ *
+ * Migration placee au namespace racine `DoctrineMigrations` (regle ABSOLUE
+ * Starseed n°11) : avec plusieurs migrations_paths, Doctrine Migrations 3.x
+ * trie par FQCN alphabetique et non par version timestamp → l'init des tables
+ * d'un module doit vivre au namespace racine pour garantir l'ordre sur base
+ * vide.
+ */
+final class Version20260527164000 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'M0 Catalog : tables category_type et category, index unique partiel.';
+    }
+
+    public function up(Schema $schema): void
+    {
+        $this->addSql(<<<'SQL'
+            CREATE TABLE category_type (
+                id INT GENERATED BY DEFAULT AS IDENTITY NOT NULL,
+                code VARCHAR(40) NOT NULL,
+                label VARCHAR(120) NOT NULL,
+                PRIMARY KEY (id)
+            )
+            SQL);
+        $this->addSql('CREATE UNIQUE INDEX uq_category_type_code ON category_type (code)');
+
+        $this->addSql(<<<'SQL'
+            CREATE TABLE category (
+                id INT GENERATED BY DEFAULT AS IDENTITY NOT NULL,
+                name VARCHAR(120) NOT NULL,
+                category_type_id INT NOT NULL,
+                deleted_at TIMESTAMP(0) WITHOUT TIME ZONE DEFAULT NULL,
+                created_at TIMESTAMP(0) WITHOUT TIME ZONE NOT NULL,
+                updated_at TIMESTAMP(0) WITHOUT TIME ZONE NOT NULL,
+                created_by INT DEFAULT NULL,
+                updated_by INT DEFAULT NULL,
+                PRIMARY KEY (id),
+                CONSTRAINT fk_category_type
+                    FOREIGN KEY (category_type_id) REFERENCES category_type (id) ON DELETE RESTRICT,
+                CONSTRAINT fk_category_created_by
+                    FOREIGN KEY (created_by) REFERENCES "user" (id) ON DELETE SET NULL,
+                CONSTRAINT fk_category_updated_by
+                    FOREIGN KEY (updated_by) REFERENCES "user" (id) ON DELETE SET NULL
+            )
+            SQL);
+
+        // Unicite (name, type) case-insensitive, seulement sur les non-soft-deleted.
+        $this->addSql(<<<'SQL'
+            CREATE UNIQUE INDEX uq_category_name_type_active
+            ON category (LOWER(name), category_type_id)
+            WHERE deleted_at IS NULL
+            SQL);
+
+        $this->addSql('CREATE INDEX idx_category_deleted_at ON category (deleted_at)');
+        $this->addSql('CREATE INDEX idx_category_type_id ON category (category_type_id)');
+        $this->addSql('CREATE INDEX idx_category_created_by ON category (created_by)');
+        $this->addSql('CREATE INDEX idx_category_updated_by ON category (updated_by)');
+    }
+
+    public function down(Schema $schema): void
+    {
+        // Ordre important : `category` porte les FK vers `category_type`.
+        $this->addSql('DROP TABLE category');
+        $this->addSql('DROP TABLE category_type');
+    }
+}