[RichardoMrMu]

改动 / Change

veadk/tracing/telemetry/portal_metrics.py 中 chat_exception_counter 用 unit="time"（duration 单位，从相邻 histogram 复制），description 为 "Number of exceptions"。改为与同文件 skill 计数器一致的 unit="1"。

chat_exception_counter was created with unit="time" (a duration unit copied from a neighboring histogram), while its description says "Number of exceptions". Align it to unit="1", matching the sibling skill counters already in this file.

 self.chat_exception_counter = self.meter.create_counter(
     name=Meters.LLM_COMPLETIONS_EXCEPTIONS,
-    unit="time",
+    unit="1",
     description="Number of exceptions occurred during chat completions",
 )

双语 PRD / bilingual PRD: prd-spec/bugfixes/2026-10-27-portal-metrics-counter-unit.md (+ .zh.md)。

测试 / Tests

新增 tests/test_portal_metrics_counter_unit.py，仅依赖标准库、不 import google.adk：

• test_chat_exception_counter_uses_count_unit：断言该 counter 单位为计数单位。
• test_sibling_counters_unchanged：范围守卫，断言 llm_invoke_counter="count"、skill_download/load_counter="1" 均未被误改。

静态实算 / Static RED/GREEN (no runtime):

• base main 2301477（unit="time"）：exception counter 断言 FAILED (RED)，sibling 守卫 PASSED。
• head 6ada3e70（unit="1"）：两项 PASSED (GREEN)。

Recorder-based runtime test in test_portal_metrics.py requires google.adk and is NOT run locally; left to CI. No runtime green is claimed.

Claim / occupancy (limited)

• In this repo, no open PR touches portal_metrics.py (57 open PRs; only 3 touch tracing, different files). Search for chat_exception_counter / portal_metrics = no matching issue.
• 此为限定结论：本仓/相关搜索范围内无 matching issue；不代表全局无人在改。No absolute "FREE" claim.
• 本改动未改公共 API、span/事件契约或依赖；仅修正遥测元数据单位。