feat: expose dependency and processing observations

.github/workflows/e2e-harness.yml

@@ -406,6 +406,7 @@ jobs:
           uv run --locked --extra server python -m pytest -vv -ra \
             tests/e2e/test_atomic_memory_search_authorization_snapshot.py \
             tests/e2e/test_atomic_memory_read_snapshot.py \
+            tests/e2e/test_server_metrics_oceanbase.py \
             tests/e2e/test_runtime_server.py -k oceanbase \
             --junitxml="$RUNNER_TEMP/atomic-memory-oceanbase-snapshots.xml"
           uv run --locked --extra server python - <<'PY'

README.md

@@ -86,6 +86,8 @@ A managed Skill holds a name, a discovery description, instructions, validation
 install or execute it: an exact approved Revision must be exported explicitly before an Agent host can discover the
 host-local projection.
 
+[Operational metrics](docs/en/docs/operate/observability.md) expose dependency observations, processing freshness, and attempt latency, including a protected metrics-only endpoint for standalone background deployments.
+
 ## Why PowerContext?
 
 - **Context lives outside the conversation.** Memory, Handoff, Experience, and Skill are server-side artifacts, not

README_CN.md

@@ -72,6 +72,8 @@ Experience 记录一个场景、一次动作、观察到的结果，以及可复
 
 一个受管的 Skill 包含名称、发现描述、指令、校验项和血缘。评审通过**不等于**安装或执行：必须先显式导出某一个明确的已通过 Revision，Agent 宿主才能发现对应的宿主内副本。
 
+[运行指标](docs/zh/docs/operate/observability.md)提供依赖状态观察、处理进度新鲜度和执行尝试延迟；独立后台部署也可使用受保护的专用指标端点。
+
 ## 为什么选 PowerContext？
 
 - **上下文活在对话之外。** Memory、Handoff、Experience、Skill 都是服务端 Artifact，不是某个 Agent 家目录里的文件。从 Codex 换到 Claude Code，或者把工作交给同事，工作本身跟着你走。

docs/en/docs/operate/configuration.md

@@ -315,9 +315,11 @@ family, or disabling built-in background families with `ARTIFACT_PROCESSING_FAMI
 before accepting work. Turning off schedules alone is insufficient because explicit requests still start workers.
 Custom Source registries remain available to synchronous SDK contexts and API-only composition.
 
-The authenticated `/metrics` endpoint exposes `powercontext_server_artifact_processing_*` observations with only a `family`
-label: Worker capacity, ready/retry queues, unacknowledged Scopes, discovery and invocation duration, completions,
+The authenticated `/metrics` endpoint exposes `powercontext_server_artifact_processing_*` observations with a bounded `family`
+label and, where applicable, `state`, `outcome`, `category`, or `reason`: Worker capacity, ready/retry queues,
+unacknowledged Scopes, discovery and invocation duration, completions,
 failures, and timeouts. Unacknowledged counts reflect the latest discovery; counters reset with the Supervisor instance.
+See [Logs, metrics, and tracing](observability.md) for freshness, state, attempt/acknowledgement, and alert semantics.
 
 The `extraction` object in `GET /v1/capabilities` separates configuration, background execution, and local observations.
 Reading this snapshot does not query the database or call a model, and does not produce an overall health verdict.
@@ -409,9 +411,13 @@ Handoff Report API routes are independently enabled by default. See
 [Use Handoff Report](../workflows/use-handoff-report.md) for selection, inspection, and export.
 
 The Artifact Processing Supervisor is enabled by the default `all` role. OceanBase deployments may run `api` and
-`background` separately; `powercontext server run --role background` starts no HTTP, MCP, or Dashboard listener, and
-multiple background candidates use the database Lease to elect one active Leader. SQLite and embedded seekdb support
-only the single-process `all` role. Automatic Topic Memory waves remain disabled until a positive interval is set;
+`background` separately. When metrics are enabled, `powercontext server run --role background` exposes `/metrics` and
+public `/health/live` using `POWERCONTEXT_SERVER_HTTP_HOST` and `POWERCONTEXT_SERVER_METRICS_BACKGROUND_PORT`
+(default `8001`); it does not serve business APIs, MCP, Dashboard, OpenAPI, or `/health/ready`.
+`/metrics` uses the same authentication and `server.observe` authorization as the API host.
+Use distinct ports for API and background processes on the same host. `POWERCONTEXT_SERVER_METRICS_ENABLED=false`
+opens no background listener. Multiple background candidates use the database Lease to elect one active Leader.
+SQLite and embedded seekdb support only the single-process `all` role. Automatic Topic Memory waves remain disabled until a positive interval is set;
 explicit flush work remains recoverable regardless of that interval. Topic workers need file-backed SQLite: configuring
 a generation model with an in-memory SQLite database is rejected before processing is advertised. Use a persistent
 `POWERCONTEXT_SERVER_DATABASE_URL`, such as `sqlite+aiosqlite:////srv/powercontext/runtime.db`.