chore(template): clean-slate template snapshot from bb4a0c7

Curated, product-agnostic snapshot of the post-story-04 tree: demo
content deleted, auth-only reference feature, web-next shell, all gates
green. Product-specific docs, ADRs 027-029, PRDs/epics/archive, editor
library traces, and product naming are curated out; generic template
repairs (coverage provider devDeps, root test:coverage script, live
lint fixes, root-only release-please) are kept. See TEMPLATE.md for
provenance, curation list, and usage.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016j8z4VHjedXDTjEDNg7qHK

docs/library-decisions/2026-05-14-@opentelemetry/sdk-trace-base.md

@@ -0,0 +1,87 @@
+---
+package: "@opentelemetry/sdk-trace-base"
+version: "^1.27.0"
+tier: core
+decision: approved
+date: 2026-05-14
+deciders: [Danijel Martinek]
+adr: adr-017
+filter-results:
+  license: Apache-2.0
+  types: native
+  maintenance: active
+  boundary-fit: pass
+  shadow-check: pass
+  eu-residency: n/a
+  cve-scan: clean
+  named-consumer: pass
+  socketRisk: clean
+verification-commands:
+  - npm view @opentelemetry/sdk-trace-base license
+  - npm view @opentelemetry/sdk-trace-base version
+  - pnpm audit --audit-level=moderate
+accepted-cves: []
+---
+
+## Filter: license
+
+<!-- Result: Apache-2.0 -->
+
+`npm view @opentelemetry/sdk-trace-base license` returns `Apache-2.0`. Apache-2.0 is on the allowlist.
+
+## Filter: types
+
+<!-- Result: native -->
+
+`@opentelemetry/sdk-trace-base` is authored in TypeScript and ships its own `.d.ts` declaration files. No separate `@types/` package is needed.
+
+## Filter: maintenance
+
+<!-- Result: active -->
+
+Actively maintained by the OpenTelemetry community on the stable 1.x track. The 1.27.x line is current; the tracing specification is stable within CNCF.
+
+## Filter: boundary-fit
+
+<!-- Result: pass -->
+
+ADR-017 §8 restricts `@opentelemetry/sdk-trace-base` to `**/instrumentation/otel/**` and app init paths. `SpanProcessor` and `ReadableSpan` types from this package are used to implement `PiiScrubSpanProcessor` in `core-shared`. `packages/core-audit` also uses `ReadableSpan` for span context in audit records.
+
+## Filter: shadow-check
+
+<!-- Result: pass -->
+
+`@opentelemetry/sdk-trace-base` is the OTel trace SDK foundation. No competing trace SDK is present in the workspace.
+
+## Filter: eu-residency
+
+<!-- Result: n/a -->
+
+`@opentelemetry/sdk-trace-base` is the tracing SDK infrastructure with no independent data transmission. Spans are forwarded through configured processors and exporters. EU residency is governed by the exporter DSN configuration.
+
+## Filter: cve-scan
+
+<!-- Result: clean -->
+
+`pnpm audit --audit-level=moderate` reports no advisories against `@opentelemetry/sdk-trace-base` at the time of this trace.
+
+## Filter: named-consumer
+
+<!-- Result: pass -->
+
+`packages/core-shared/src/instrumentation/otel/pii-scrub-span-processor.ts` implements `SpanProcessor` from `@opentelemetry/sdk-trace-base` to scrub PII attributes before spans reach the Sentry exporter (ADR-017 §7). `packages/core-audit` uses `ReadableSpan` for audit record correlation.
+
+## Prompt: replaces
+
+The former `SentryTracer` which called Sentry SDK span methods directly. `@opentelemetry/sdk-trace-base` provides the `SpanProcessor` extension point that enables the `PiiScrubSpanProcessor` — a vendor-neutral, pre-export PII scrubbing layer.
+
+## Prompt: migration-cost-out
+
+Hard. `@opentelemetry/sdk-trace-base` types (`SpanProcessor`, `ReadableSpan`) are used in both `core-shared` PII scrub implementation and `core-audit`. Replacing it means adopting a different span processing abstraction and rewriting both the processor and audit span-context integration.
+
+## Prompt: alternatives-considered
+
+1. **Sentry `beforeSendTransaction` hook** — Sentry-native PII scrubbing hook. Rejected in ADR-017 §7: runs inside Sentry after OTel conversion; the OTel processor layer runs earlier and is vendor-agnostic, so any future exporter also sees clean data.
+2. **No span processor, rely on Sentry scrubbing rules** — Rejected: Sentry-specific configuration; future exporter additions would need their own scrubbing configured separately.
+
+See ADR-017 for the full decision rationale.