fix(telemetry): review fixes — flush/shutdown ordering, session retirement, whole-exporter passthrough

Three review findings, each pinned by a red test first:

- The OTel backend retains the latest turn-boundary flush promise and
  shutdown() awaits it before provider.shutdown(): the SDK's
  concurrent-flush guard makes the shutdown-internal flush return early
  while one is in flight, silently dropping everything enqueued after
  the flush snapshot (including the coordinator's dispose-time shutdown
  markers).
- The coordinator retires sessions from the adopted set on
  session/disposed (mirroring the persistence coordinator): a long-lived
  backend no longer retains closed sessions and their event logs, and
  final unload no longer stamps shutdown markers for dead sessions.
- The exporter config passes through whole to OTLPLogExporter and its
  type/JSDoc now advertise the full OTLPExporterNodeConfigBase shape:
  rebuilding url/headers only silently dropped documented SDK options
  (timeoutMillis, compression, keepAlive, ...).

docs/config-catalog.md

@@ -1059,12 +1059,15 @@ Requires: `sessions`
  * must fail at plugin load, not at first export.
  */
 export interface Config {
-  /** Passed verbatim to the SDK's OTLP/HTTP log exporter. */
-  exporter?: {
+  /**
+   * Passed verbatim to the SDK's OTLP/HTTP log exporter — the complete
+   * `OTLPExporterNodeConfigBase` shape (`headers`, `timeoutMillis`,
+   * `compression`, `keepAlive`, …), owned and documented by the SDK. `url`
+   * is the one field this package requires and validates itself.
+   */
+  exporter?: OTLPExporterNodeConfigBase & {
     /** Full logs endpoint (e.g. `https://collector.example.com/v1/logs`). Required; validated at plugin load. */
     url?: string
-    /** Extra request headers (auth etc.); owned and sent by the SDK exporter. */
-    headers?: Record<string, string>
   }
   /**
    * Passed verbatim to `BatchLogRecordProcessor` (minus the exporter slot,
@@ -1074,9 +1077,9 @@ export interface Config {
 }
 ```
 
-Depends on: `BatchLogRecordProcessorOptions` (`@opentelemetry/sdk-logs`)
+Depends on: `BatchLogRecordProcessorOptions` (`@opentelemetry/sdk-logs`) · `OTLPExporterNodeConfigBase` (`@opentelemetry/otlp-exporter-base`)
 
-Source: [`packages/telemetry/session-telemetry-otel/src/index.ts:39`](../packages/telemetry/session-telemetry-otel/src/index.ts)
+Source: [`packages/telemetry/session-telemetry-otel/src/index.ts:40`](../packages/telemetry/session-telemetry-otel/src/index.ts)
 
 ## `@deepseek-ai/dsh-session-title`
 

docs/cordis-catalog/services.md

@@ -1554,7 +1554,7 @@ flush?(): void
 abstract shutdown(): Promise<void>
 ```
 
-Source: [`packages/telemetry/session-telemetry/src/index.ts:125`](../../packages/telemetry/session-telemetry/src/index.ts)
+Source: [`packages/telemetry/session-telemetry/src/index.ts:129`](../../packages/telemetry/session-telemetry/src/index.ts)
 
 ## `ctx.tokenMeter` — `TokenMeterService`
 

docs/event-producer-consumer.md

@@ -34,7 +34,7 @@ This matrix shows which packages dispatch each harness-owned event and which pac
 | `goal/changed` | `emit` | [`packages/goal/goal/src/types.ts:167`](../packages/goal/goal/src/types.ts) | [`goal`](../packages/goal/goal) (`emit`) | [`goal-session`](../packages/goal/goal-session) |
 | `llm/stream` | `waterfall` | [`packages/llm/llm/src/index.ts:52`](../packages/llm/llm/src/index.ts) | [`llm`](../packages/llm/llm) (`waterfall`) | [`agent-loop`](../packages/core/agent-loop), [`llm`](../packages/llm/llm), [`llm-replay`](../packages/support/llm-replay), [`session-checkpoint-policy`](../packages/session-persistence/session-checkpoint-policy), [`session-title`](../packages/session-title/session-title) |
 | `session/created` | `emit` | [`packages/core/session/src/index.ts:79`](../packages/core/session/src/index.ts) | [`session`](../packages/core/session) (`events.dispatch`) | [`compact`](../packages/compact/compact), [`goal`](../packages/goal/goal), [`hook-protocol`](../packages/hooks/hook-protocol), [`jsonrpc`](../packages/ui/jsonrpc), [`llm-retry`](../packages/llm/llm-retry), `runtime`, [`session`](../packages/core/session), [`session-persistence`](../packages/session-persistence/session-persistence), [`session-telemetry`](../packages/telemetry/session-telemetry), [`user-approval`](../packages/ui/user-approval) |
-| `session/disposed` | `emit` | [`packages/core/session/src/index.ts:89`](../packages/core/session/src/index.ts) | [`session`](../packages/core/session) (`events.dispatch`) | [`agent-loop`](../packages/core/agent-loop), `runtime`, [`session-persistence`](../packages/session-persistence/session-persistence), [`session-title`](../packages/session-title/session-title) |
+| `session/disposed` | `emit` | [`packages/core/session/src/index.ts:89`](../packages/core/session/src/index.ts) | [`session`](../packages/core/session) (`events.dispatch`) | [`agent-loop`](../packages/core/agent-loop), `runtime`, [`session-persistence`](../packages/session-persistence/session-persistence), [`session-telemetry`](../packages/telemetry/session-telemetry), [`session-title`](../packages/session-title/session-title) |
 | `session/event` | `emit` | [`packages/core/session/src/index.ts:101`](../packages/core/session/src/index.ts) | [`session`](../packages/core/session) (`events.dispatch`) | [`acp`](../packages/ui/acp), [`cli-demo`](../packages/examples/cli-demo), [`compact`](../packages/compact/compact), [`goal`](../packages/goal/goal), [`goal-session`](../packages/goal/goal-session), [`hook-protocol`](../packages/hooks/hook-protocol), [`jsonrpc`](../packages/ui/jsonrpc), `runtime`, [`session`](../packages/core/session), [`session-persistence`](../packages/session-persistence/session-persistence), [`session-telemetry`](../packages/telemetry/session-telemetry), [`session-title`](../packages/session-title/session-title), [`token-meter`](../packages/llm/token-meter), [`tui`](../packages/ui/tui), [`user-approval`](../packages/ui/user-approval), [`workspace-context`](../packages/context/workspace-context) |
 | `session/flush` | `parallel` | [`packages/core/session/src/index.ts:111`](../packages/core/session/src/index.ts) | [`session`](../packages/core/session) (`events.dispatch`) | [`session-persistence`](../packages/session-persistence/session-persistence), [`session-telemetry`](../packages/telemetry/session-telemetry) |
 | `subagent/end` | `emit` | [`packages/subagent/subagent/src/index.ts:139`](../packages/subagent/subagent/src/index.ts) | [`subagent`](../packages/subagent/subagent) (`events.dispatch`) | [`hooks-claude`](../packages/hooks/hooks-claude), [`jsonrpc`](../packages/ui/jsonrpc), [`subagent`](../packages/subagent/subagent) |