refactor(taosctl): dashboard uses shared positive_int validator (#1403)

Replace the dashboard group's inline _positive_int with the shared
tinyagentos/cli/taosctl/argtypes.positive_int (landed in #1401), removing the
duplicate now that both are on dev. Behaviour unchanged; --limit still rejects
non-positive values at parse time.

Author: jaylfc

tinyagentos/cli/taosctl/commands/dashboard.py

@@ -10,17 +10,11 @@
 """
 from __future__ import annotations
 
-import argparse
 from urllib.parse import quote
 
-NOUN = "dashboard"
-
+from tinyagentos.cli.taosctl.argtypes import positive_int
 
-def _positive_int(value: str) -> int:
-    iv = int(value)
-    if iv <= 0:
-        raise argparse.ArgumentTypeError("must be a positive integer")
-    return iv
+NOUN = "dashboard"
 
 
 def register(subparsers) -> None:
@@ -47,7 +41,7 @@ def register(subparsers) -> None:
     bp.set_defaults(func=_backends)
 
     ap = verbs.add_parser("activity", help="Recent dashboard activity")
-    ap.add_argument("--limit", type=_positive_int, default=15)
+    ap.add_argument("--limit", type=positive_int, default=15)
     ap.set_defaults(func=_activity)
 
     mp = verbs.add_parser("metrics", help="Query a named time-series metric")