feat: add Z12/Z13 bind APIs, stock import, and sync docs

Enable auto default sync channels on agent activate, bind-code/phone confirm flows, publish ALTER, and align admin/yuheng docs with the production bind path.

platform/internal/schema/alter.go

@@ -0,0 +1,92 @@
+package schema
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"strings"
+
+	"aijianzhan/platform/internal/blueprint"
+)
+
+// BuildPostgresAlterDDL 对比蓝图与已有表，生成 ADD COLUMN IF NOT EXISTS（Z11a）。
+// db 可为 nil：则只返回空（调用方应先 CREATE TABLE）。
+func BuildPostgresAlterDDL(ctx context.Context, db *sql.DB, bp *blueprint.Blueprint) ([]string, error) {
+	if bp == nil || bp.Storage.SchemaName == "" {
+		return nil, fmt.Errorf("schema_name empty")
+	}
+	if db == nil {
+		return nil, nil
+	}
+	schemaName := bp.Storage.SchemaName
+	var stmts []string
+	for _, e := range bp.Entities {
+		existing, err := listTableColumns(ctx, db, schemaName, e.Table)
+		if err != nil {
+			return nil, err
+		}
+		if existing == nil {
+			// 表尚不存在：由 CREATE TABLE IF NOT EXISTS 处理
+			continue
+		}
+		for _, f := range e.Fields {
+			if _, ok := existing[f.Name]; ok {
+				continue
+			}
+			sqlType, err := mapType(f)
+			if err != nil {
+				return nil, err
+			}
+			// 存量表补列一律可空，避免非空约束导致迁库失败
+			stmts = append(stmts, fmt.Sprintf(
+				`ALTER TABLE %s.%s ADD COLUMN IF NOT EXISTS %s %s`,
+				quoteIdent(schemaName), quoteIdent(e.Table), quoteIdent(f.Name), sqlType,
+			))
+		}
+	}
+	return stmts, nil
+}
+
+func listTableColumns(ctx context.Context, db *sql.DB, schemaName, table string) (map[string]struct{}, error) {
+	const q = `
+SELECT column_name FROM information_schema.columns
+WHERE table_schema = $1 AND table_name = $2`
+	rows, err := db.QueryContext(ctx, q, schemaName, table)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	out := map[string]struct{}{}
+	found := false
+	for rows.Next() {
+		found = true
+		var name string
+		if err := rows.Scan(&name); err != nil {
+			return nil, err
+		}
+		out[name] = struct{}{}
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	if !found {
+		return nil, nil
+	}
+	return out, nil
+}
+
+// MergeDDL 将 alter 语句追加到 create ddl 之后。
+func MergeDDL(create, alter []string) []string {
+	if len(alter) == 0 {
+		return create
+	}
+	out := make([]string, 0, len(create)+len(alter))
+	out = append(out, create...)
+	out = append(out, alter...)
+	return out
+}
+
+// Quote for tests
+func normalizeSchemaTable(s string) string {
+	return strings.TrimSpace(s)
+}