fix(db): use correct context key 'user_id' in document handlers

The middleware sets c.Set("user_id", ...) but the /db/:collection
handlers were reading c.GetString("userID") (camelCase mismatch),
producing an empty user_id. POST/PUT/DELETE then failed with
documents_user_id_fkey FK violations (23503), and GET silently
returned []. Tests masked the bug because they pre-set the wrong key.

Aligns with every other handler in the repo (auth, admin, buckets,
analytics, quota, provisioning, mcp) which all use "user_id".

Author: tevfik

internal/api/db/handlers.go

@@ -35,7 +35,7 @@ func (h *Handler) RegisterRoutes(r *gin.RouterGroup) {
 // CreateDoc creates a user document.
 // POST /db/:collection
 func (h *Handler) CreateDoc(c *gin.Context) {
-	userID := c.GetString("userID")
+	userID := c.GetString("user_id")
 	collection := c.Param("collection")
 
 	var doc map[string]interface{}
@@ -57,7 +57,7 @@ func (h *Handler) CreateDoc(c *gin.Context) {
 // ListDocs lists user documents in a collection.
 // GET /db/:collection
 func (h *Handler) ListDocs(c *gin.Context) {
-	userID := c.GetString("userID")
+	userID := c.GetString("user_id")
 	collection := c.Param("collection")
 
 	docs, err := h.Store.ListDocuments(userID, collection)
@@ -77,7 +77,7 @@ func (h *Handler) ListDocs(c *gin.Context) {
 // GetDoc gets a specific user document.
 // GET /db/:collection/:id
 func (h *Handler) GetDoc(c *gin.Context) {
-	userID := c.GetString("userID")
+	userID := c.GetString("user_id")
 	collection := c.Param("collection")
 	docID := c.Param("id")
 
@@ -99,7 +99,7 @@ func (h *Handler) GetDoc(c *gin.Context) {
 // UpdateDoc updates a specific user document.
 // PUT /db/:collection/:id
 func (h *Handler) UpdateDoc(c *gin.Context) {
-	userID := c.GetString("userID")
+	userID := c.GetString("user_id")
 	collection := c.Param("collection")
 	docID := c.Param("id")
 
@@ -126,7 +126,7 @@ func (h *Handler) UpdateDoc(c *gin.Context) {
 // DeleteDoc deletes a specific user document.
 // DELETE /db/:collection/:id
 func (h *Handler) DeleteDoc(c *gin.Context) {
-	userID := c.GetString("userID")
+	userID := c.GetString("user_id")
 	collection := c.Param("collection")
 	docID := c.Param("id")
 

internal/api/db/handlers_test.go

@@ -32,7 +32,7 @@ func setupTestEnv(t *testing.T) (*Handler, storage.Provider, func()) {
 
 func userMiddleware(userID string) gin.HandlerFunc {
 	return func(c *gin.Context) {
-		c.Set("userID", userID)
+		c.Set("user_id", userID)
 		c.Set("user_id", userID)
 		c.Next()
 	}