feat(whatsapp): 🎉 Add extended sending and template management

* Implemented new endpoints for sending various message types:
  - Audio
  - Sticker
  - Location
  - Contacts
  - Interactive messages
  - Template messages
  - Flow messages
  - Reactions
  - Marking messages as read

* Added template management endpoints:
  - List templates
  - Upload templates
  - Delete templates

* Introduced flow management endpoints:
  - List flows
  - Create flows
  - Get flow details
  - Upload flow assets
  - Publish flows
  - Delete flows

* Added phone number management endpoints:
  - List phone numbers
  - Request verification code
  - Verify code

* Enhanced media management with delete media endpoint.

* Updated dependencies.

pkg/whatsapp/businessapi/flows.go

@@ -0,0 +1,71 @@
+package businessapi
+
+import (
+	"context"
+	"net/url"
+)
+
+// ListFlows returns all flows for the business account.
+func (c *Client) ListFlows(ctx context.Context) (*FlowListResponse, error) {
+	if c.config.BusinessAccountID == "" {
+		return nil, errNoBusinessAccount
+	}
+
+	params := url.Values{
+		"fields": {"id,name,status,categories,created_at,updated_at,endpoint_url,preview_url,signed_preview_url,signed_flow_url"},
+	}
+
+	var resp FlowListResponse
+	if err := c.graphAPIGet(ctx, c.config.BusinessAccountID+"/flows", params, &resp); err != nil {
+		return nil, err
+	}
+	return &resp, nil
+}
+
+// CreateFlow creates a new flow and returns its ID.
+func (c *Client) CreateFlow(ctx context.Context, flow FlowCreateRequest) (*FlowCreateResponse, error) {
+	if c.config.BusinessAccountID == "" {
+		return nil, errNoBusinessAccount
+	}
+
+	var resp FlowCreateResponse
+	if err := c.graphAPIPost(ctx, c.config.BusinessAccountID+"/flows", flow, &resp); err != nil {
+		return nil, err
+	}
+	return &resp, nil
+}
+
+// GetFlow returns details for a single flow.
+func (c *Client) GetFlow(ctx context.Context, flowID string) (*FlowInfo, error) {
+	params := url.Values{
+		"fields": {"id,name,status,categories,created_at,updated_at,endpoint_url,preview_url,signed_preview_url,signed_flow_url"},
+	}
+
+	var resp FlowInfo
+	if err := c.graphAPIGet(ctx, flowID, params, &resp); err != nil {
+		return nil, err
+	}
+	return &resp, nil
+}
+
+// UpdateFlowAssets uploads a screens JSON definition to an existing flow (must be in DRAFT).
+func (c *Client) UpdateFlowAssets(ctx context.Context, flowID string, screensJSON string) error {
+	fields := map[string]string{
+		"asset_type": "SCREENS_JSON",
+		"asset_data": screensJSON,
+	}
+
+	var resp FlowActionResponse
+	return c.graphAPIPostForm(ctx, flowID+"/assets", fields, &resp)
+}
+
+// PublishFlow transitions a DRAFT flow to PUBLISHED.
+func (c *Client) PublishFlow(ctx context.Context, flowID string) error {
+	var resp FlowActionResponse
+	return c.graphAPIPost(ctx, flowID+"?action=PUBLISH", nil, &resp)
+}
+
+// DeleteFlow permanently removes a flow.
+func (c *Client) DeleteFlow(ctx context.Context, flowID string) error {
+	return c.graphAPIDelete(ctx, flowID, nil)
+}