fix(apps): make db --environment optional, auto-select branch server-side

All db shortcuts defaulted --environment to "dev", which forced single-env
apps (whose DB lives on the online branch, with no dev branch) to fail with
"Invalid DB Branch: dev" unless the user explicitly passed --environment
online.

Change the default to empty: when --environment is omitted the CLI sends no
env, letting the server pick the branch by the app's multi-env state
(multi-env → dev, single-env → online), matching miaoda-cli's behavior of
not carrying dbBranch when unset. Explicit --environment dev|online is
unchanged; explicit dev on a single-env app still errors as expected.

- 10 db shortcuts: dbEnvFlags default "dev" → "" (+db-execute, +db-table-list,
  +db-table-get, +db-quota-get, +db-data-export, +db-data-import,
  +db-changelog-list, +db-audit-list/-set/-status)
- dry-run e2e assertions updated: default env is now unset, not "dev"
- skill docs (lark-apps-db, lark-apps-db-execute) describe the auto-select

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: chenxingyang1019

shortcuts/apps/apps_db_audit_list.go

@@ -40,7 +40,7 @@ var AppsDBAuditList = common.Shortcut{
 		{Name: "until", Desc: "filter: event at or before; same formats as --since"},
 		{Name: "page-size", Type: "int", Default: "20", Desc: "page size"},
 		{Name: "page-token", Desc: "pagination cursor from previous response"},
-	}, dbEnvFlags("dev", []string{"dev", "online"}, "target db environment (default dev; use online for the online environment, or for an app whose DB is not multi-env)")...),
+	}, dbEnvFlags("", []string{"dev", "online"}, "target db environment; leave unset to auto-select (multi-env app uses dev, single-env uses online), or pass dev/online")...),
 	Validate: func(ctx context.Context, rctx *common.RuntimeContext) error {
 		if _, err := requireAppID(rctx.Str("app-id")); err != nil {
 			return err

shortcuts/apps/apps_db_audit_set.go

@@ -35,7 +35,7 @@ var AppsDBAuditEnable = common.Shortcut{
 		{Name: "app-id", Desc: "Miaoda app id", Required: true},
 		{Name: "table", Desc: "table to enable audit for", Required: true},
 		{Name: "retention", Default: "7d", Enum: auditRetentions, Desc: "how long to keep audit logs"},
-	}, dbEnvFlags("dev", []string{"dev", "online"}, "target db environment (default dev; use online for the online environment, or for an app whose DB is not multi-env)")...),
+	}, dbEnvFlags("", []string{"dev", "online"}, "target db environment; leave unset to auto-select (multi-env app uses dev, single-env uses online), or pass dev/online")...),
 	Validate: func(ctx context.Context, rctx *common.RuntimeContext) error {
 		if _, err := requireAppID(rctx.Str("app-id")); err != nil {
 			return err
@@ -96,7 +96,7 @@ var AppsDBAuditDisable = common.Shortcut{
 	Flags: append([]common.Flag{
 		{Name: "app-id", Desc: "Miaoda app id", Required: true},
 		{Name: "table", Desc: "table to disable audit for", Required: true},
-	}, dbEnvFlags("dev", []string{"dev", "online"}, "target db environment (default dev; use online for the online environment, or for an app whose DB is not multi-env)")...),
+	}, dbEnvFlags("", []string{"dev", "online"}, "target db environment; leave unset to auto-select (multi-env app uses dev, single-env uses online), or pass dev/online")...),
 	Validate: func(ctx context.Context, rctx *common.RuntimeContext) error {
 		if _, err := requireAppID(rctx.Str("app-id")); err != nil {
 			return err

shortcuts/apps/apps_db_audit_status.go

@@ -30,7 +30,7 @@ var AppsDBAuditStatus = common.Shortcut{
 	Flags: append([]common.Flag{
 		{Name: "app-id", Desc: "Miaoda app id", Required: true},
 		{Name: "table", Desc: "show status for a single table (default: all configured tables)"},
-	}, dbEnvFlags("dev", []string{"dev", "online"}, "target db environment (default dev; use online for the online environment, or for an app whose DB is not multi-env)")...),
+	}, dbEnvFlags("", []string{"dev", "online"}, "target db environment; leave unset to auto-select (multi-env app uses dev, single-env uses online), or pass dev/online")...),
 	Validate: func(ctx context.Context, rctx *common.RuntimeContext) error {
 		if _, err := requireAppID(rctx.Str("app-id")); err != nil {
 			return err

shortcuts/apps/apps_db_changelog_list.go

@@ -39,7 +39,7 @@ var AppsDBChangelogList = common.Shortcut{
 		{Name: "until", Desc: "filter: changed at or before; same formats as --since"},
 		{Name: "page-size", Type: "int", Default: "20", Desc: "page size"},
 		{Name: "page-token", Desc: "pagination cursor from previous response"},
-	}, dbEnvFlags("dev", []string{"dev", "online"}, "target db environment (default dev; use online for the online environment, or for an app whose DB is not multi-env)")...),
+	}, dbEnvFlags("", []string{"dev", "online"}, "target db environment; leave unset to auto-select (multi-env app uses dev, single-env uses online), or pass dev/online")...),
 	Validate: func(ctx context.Context, rctx *common.RuntimeContext) error {
 		if _, err := requireAppID(rctx.Str("app-id")); err != nil {
 			return err

shortcuts/apps/apps_db_data_export.go

@@ -47,7 +47,7 @@ var AppsDBDataExport = common.Shortcut{
 		{Name: "table", Desc: "source table", Required: true},
 		{Name: "output", Desc: "local output path; extension picks format .csv/.json/.sql (default: <table>.csv)"},
 		{Name: "limit", Type: "int", Default: "5000", Desc: "max rows to export (1..5000)"},
-	}, dbEnvFlags("dev", []string{"dev", "online"}, "source db environment (default dev; use online for the online environment, or for an app whose DB is not multi-env)")...),
+	}, dbEnvFlags("", []string{"dev", "online"}, "source db environment; leave unset to auto-select (multi-env app uses dev, single-env uses online), or pass dev/online")...),
 	Validate: func(ctx context.Context, rctx *common.RuntimeContext) error {
 		if _, err := requireAppID(rctx.Str("app-id")); err != nil {
 			return err

shortcuts/apps/apps_db_data_import.go

@@ -44,7 +44,7 @@ var AppsDBDataImport = common.Shortcut{
 		{Name: "app-id", Desc: "Miaoda app id", Required: true},
 		{Name: "file", Desc: "local data file (.csv/.json), relative to cwd", Required: true},
 		{Name: "table", Desc: "target table (default: file name without extension)"},
-	}, dbEnvFlags("dev", []string{"dev", "online"}, "target db environment (default dev; use online for the online environment, or for an app whose DB is not multi-env)")...),
+	}, dbEnvFlags("", []string{"dev", "online"}, "target db environment; leave unset to auto-select (multi-env app uses dev, single-env uses online), or pass dev/online")...),
 	Validate: func(ctx context.Context, rctx *common.RuntimeContext) error {
 		if _, err := requireAppID(rctx.Str("app-id")); err != nil {
 			return err

shortcuts/apps/apps_db_execute.go

@@ -66,7 +66,7 @@ var AppsDBExecute = common.Shortcut{
 		{Name: "sql", Desc: "SQL text; use - to read stdin. Mutually exclusive with --file",
 			Input: []string{common.Stdin}},
 		{Name: "file", Desc: "path to a .sql file (relative to cwd). Mutually exclusive with --sql"},
-	}, dbEnvFlags("dev", []string{"dev", "online"}, "target db environment (default dev; use online for the online environment, or for an app whose DB is not multi-env)")...),
+	}, dbEnvFlags("", []string{"dev", "online"}, "target db environment; leave unset to auto-select (multi-env app uses dev, single-env uses online), or pass dev/online")...),
 	Validate: func(ctx context.Context, rctx *common.RuntimeContext) error {
 		if _, err := requireAppID(rctx.Str("app-id")); err != nil {
 			return err

shortcuts/apps/apps_db_quota_get.go

@@ -29,7 +29,7 @@ var AppsDBQuotaGet = common.Shortcut{
 	HasFormat: true,
 	Flags: append([]common.Flag{
 		{Name: "app-id", Desc: "Miaoda app id", Required: true},
-	}, dbEnvFlags("dev", []string{"dev", "online"}, "target db environment (default dev; use online for the online environment, or for an app whose DB is not multi-env)")...),
+	}, dbEnvFlags("", []string{"dev", "online"}, "target db environment; leave unset to auto-select (multi-env app uses dev, single-env uses online), or pass dev/online")...),
 	Validate: func(ctx context.Context, rctx *common.RuntimeContext) error {
 		if _, err := requireAppID(rctx.Str("app-id")); err != nil {
 			return err

shortcuts/apps/apps_db_table_get.go

@@ -37,7 +37,7 @@ var AppsDBTableGet = common.Shortcut{
 	Flags: append([]common.Flag{
 		{Name: "app-id", Desc: "app id", Required: true},
 		{Name: "table", Desc: "table name", Required: true},
-	}, dbEnvFlags("dev", []string{"dev", "online"}, "target db environment (default dev; use online for the online environment, or for an app whose DB is not multi-env)")...),
+	}, dbEnvFlags("", []string{"dev", "online"}, "target db environment; leave unset to auto-select (multi-env app uses dev, single-env uses online), or pass dev/online")...),
 	Validate: func(ctx context.Context, rctx *common.RuntimeContext) error {
 		if _, err := requireAppID(rctx.Str("app-id")); err != nil {
 			return err

shortcuts/apps/apps_db_table_list.go

@@ -42,7 +42,7 @@ var AppsDBTableList = common.Shortcut{
 		{Name: "app-id", Desc: "app id", Required: true},
 		{Name: "page-size", Type: "int", Default: "20", Desc: "page size"},
 		{Name: "page-token", Desc: "pagination cursor from previous response"},
-	}, dbEnvFlags("dev", []string{"dev", "online"}, "target db environment (default dev; use online for the online environment, or for an app whose DB is not multi-env)")...),
+	}, dbEnvFlags("", []string{"dev", "online"}, "target db environment; leave unset to auto-select (multi-env app uses dev, single-env uses online), or pass dev/online")...),
 	Validate: func(ctx context.Context, rctx *common.RuntimeContext) error {
 		if _, err := requireAppID(rctx.Str("app-id")); err != nil {
 			return err