feat(files): implement file storage functionality with save, load, and list operations

internal/types/thought.go

@@ -7,12 +7,44 @@ import (
 )
 
 type ThoughtMetadata struct {
-	People         []string `json:"people"`
-	ActionItems    []string `json:"action_items"`
-	DatesMentioned []string `json:"dates_mentioned"`
-	Topics         []string `json:"topics"`
-	Type           string   `json:"type"`
-	Source         string   `json:"source"`
+	People         []string            `json:"people"`
+	ActionItems    []string            `json:"action_items"`
+	DatesMentioned []string            `json:"dates_mentioned"`
+	Topics         []string            `json:"topics"`
+	Type           string              `json:"type"`
+	Source         string              `json:"source"`
+	Attachments    []ThoughtAttachment `json:"attachments,omitempty"`
+}
+
+type ThoughtAttachment struct {
+	FileID    uuid.UUID `json:"file_id"`
+	Name      string    `json:"name"`
+	MediaType string    `json:"media_type"`
+	Kind      string    `json:"kind,omitempty"`
+	SizeBytes int64     `json:"size_bytes"`
+	SHA256    string    `json:"sha256,omitempty"`
+}
+
+type StoredFile struct {
+	ID        uuid.UUID  `json:"id"`
+	ThoughtID *uuid.UUID `json:"thought_id,omitempty"`
+	ProjectID *uuid.UUID `json:"project_id,omitempty"`
+	Name      string     `json:"name"`
+	MediaType string     `json:"media_type"`
+	Kind      string     `json:"kind"`
+	Encoding  string     `json:"encoding"`
+	SizeBytes int64      `json:"size_bytes"`
+	SHA256    string     `json:"sha256"`
+	Content   []byte     `json:"-"`
+	CreatedAt time.Time  `json:"created_at"`
+	UpdatedAt time.Time  `json:"updated_at"`
+}
+
+type StoredFileFilter struct {
+	Limit     int
+	ThoughtID *uuid.UUID
+	ProjectID *uuid.UUID
+	Kind      string
 }
 
 type Thought struct {