refactor(telemetry): replay feedback sessions without buffering

packages/telemetry/session-telemetry-otel/README.md

@@ -2,7 +2,7 @@
 
 English | [中文](README.zh.md)
 
-The OpenTelemetry backend for [the telemetry seam](../session-telemetry/) — the only entry a deployment loads. Its `mode` decides whether the seam hands records over immediately, releases them only at recorded feedback, or keeps telemetry local. Uploading modes compose the OTel JS SDK as-is (`LoggerProvider` → `BatchLogRecordProcessor` → OTLP/HTTP log exporter) and map each handed-over record onto `logger.emit()`, under two instrumentation scopes: ledger records on `@deepseek-ai/dsh-session-telemetry-otel`, operational records on `@deepseek-ai/dsh-session-telemetry-otel/ops`. Resource identity (`service.name`/`service.version`) comes from `dsh-llm`'s `APP_IDENTITY`, the same source the attribution headers use.
+The OpenTelemetry backend for [the telemetry seam](../session-telemetry/) — the only entry a deployment loads. Its `mode` decides whether the seam follows session events live, replays the canonical log only at recorded feedback, or keeps telemetry local. Uploading modes compose the OTel JS SDK as-is (`LoggerProvider` → `BatchLogRecordProcessor` → OTLP/HTTP log exporter) and map each handed-over record onto `logger.emit()`, under two instrumentation scopes: ledger records on `@deepseek-ai/dsh-session-telemetry-otel`, operational records on `@deepseek-ai/dsh-session-telemetry-otel/ops`. Resource identity (`service.name`/`service.version`) comes from `dsh-llm`'s `APP_IDENTITY`, the same source the attribution headers use.
 
 ## Config
 
@@ -21,14 +21,14 @@ The OpenTelemetry backend for [the telemetry seam](../session-telemetry/) — th
 | `mode` | Behavior |
 |---|---|
 | `FULL` | Default. Each projected record, including lifecycle ops records, is handed to the OTel SDK immediately. |
-| `FEEDBACK_ONLY` | Each `feedback/record` releases the redacted, projected session prefix through that event. Later records wait for another feedback event and remain local if none arrives. |
+| `FEEDBACK_ONLY` | Each `feedback/record` replays, projects, and redacts the canonical session-log suffix through that event. Later records wait for another feedback event and remain local if none arrives. |
 | `DISABLED` | No coordinator, provider, processor, or exporter is constructed. No telemetry record leaves the process. A `feedback/record` logs `session telemetry is DISABLED; nothing will be shared and this feedback remains local`; the event remains in the local session log. |
 
 `exporter.url` is required in `FULL` and `FEEDBACK_ONLY`, has no default, and must parse as `http(s)`; it is optional and unused in `DISABLED`. Uploading modes also reject a non-positive-integer `processor.maxExportBatchSize`, which the SDK accepts but then hangs on at shutdown. Everything else is the SDK's option shape, owned and documented by the SDK, and both blocks pass through whole: every `OTLPExporterNodeConfigBase` field (`headers`, `timeoutMillis`, `compression`, `keepAlive`, …) reaches the exporter, and batching, export cadence (`scheduledDelayMillis`), retry, queue bounds, and loss policy under sustained failure are the SDK's documented behavior, tuned through the `processor` passthrough. The backend deliberately implements no `flush()`: the batch processor is the only flusher in the process, which is what makes `shutdown()`'s drain complete.
 
 ## What leaves the machine
 
-In uploading modes, records carry the complete `event.data` as the seam's `telemetry/record` waterfall returns it — user and assistant message content, tool arguments and results (command output, file contents), the full system prompt and tool schemas (`request/header`), todo text, compaction summaries, hook `stderrSummary`, feedback text, and the session `cwd` (a local path). The seam ships no redaction rules: with no `telemetry/record` listener mounted, that is the raw captured copy, so a deployment exporting beyond a trusted boundary mounts its own rules (see [the seam README](../session-telemetry/README.md#the-redact-waterfall)). Provider credentials never appear regardless: adapter API keys are constructor parameters, not session events, so they are structurally absent from the log and therefore from telemetry. `DISABLED` does not construct the SDK pipeline or hand any capture to a backend.
+In uploading modes, records carry the complete `event.data` as the seam's `telemetry/record` waterfall returns it — user and assistant message content, tool arguments and results (command output, file contents), the full system prompt and tool schemas (`request/header`), todo text, compaction summaries, hook `stderrSummary`, feedback text, and the session `cwd` (a local path). The seam ships no redaction rules: with no `telemetry/record` listener mounted, that is the raw captured copy, so a deployment exporting beyond a trusted boundary mounts its own rules (see [the seam README](../session-telemetry/README.md#the-redact-waterfall)). `FULL` runs redaction at append time; `FEEDBACK_ONLY` retains no telemetry copy and runs the currently mounted rules when feedback triggers canonical-log replay. Provider credentials never appear regardless: adapter API keys are constructor parameters, not session events, so they are structurally absent from the log and therefore from telemetry. `DISABLED` does not construct the SDK pipeline or hand any capture to a backend.
 
 ## Field mapping
 
@@ -46,4 +46,4 @@ None; this package neither assembles nor sends a provider request.
 
 - **Upstream experimental tree** — `@opentelemetry/sdk-logs` is still published from the upstream experimental tree; SDK API churn lands here and only here — the seam contract does not move.
 - **No live-collector coverage** — every test exports to a local mock collector; the keyless Loader-composition e2e (`tests/loader-composition.e2e.ts`) covers the wire shape on every run, and behavior against a real OTLP deployment (auth, TLS, throttling) is the SDK exporter's documented territory.
-- **Feedback-only memory** — each session retains deep-copied, redacted projected records in memory until feedback releases them or the session becomes unreachable. There is no durable pre-feedback spool; a crash before feedback uploads nothing.
+- **Feedback-time snapshot** — `FEEDBACK_ONLY` retains no telemetry-owned copy before feedback. It reads and redacts the current canonical log when feedback is recorded; a crash before feedback uploads nothing, and policy changes before feedback affect what that replay exports.