Move docs/ package mirror into document-navigator plugin

Relocate the ~6k-file docs tree from the repo root into
plugins/document-navigator/docs/ so the plugin is self-contained and
portable. docs/superpowers/ (specs and plans) stays at the repo root.

Moved via cp+rm rather than git mv because directory rename() fails with
EPERM on this WSL /mnt DrvFs mount; git rename-detection pairs the
identical-content files at commit time.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

plugins/document-navigator/docs/communication/emails/email-templates/src/telemetry/telemetry.md

@@ -0,0 +1,81 @@
+# telemetry
+
+<!-- begin:auto-docs -->
+_(no submodules)_
+<!-- end:auto-docs -->
+
+## Purpose
+
+Exposes the OpenTelemetry instrument set published by
+`@suaveplan/email-templates`. Every public render or registry mutation
+emits a counter (and where useful, a duration histogram) so operators can
+build dashboards without instrumenting consumers themselves.
+
+The instrument set is constructed lazily on first access — importing this
+module does NOT create a meter or instruments, satisfying the
+"side-effects: false" contract in `package.json`. Once constructed, the
+set is cached and the same object reference is returned forever (the
+metric exporter receives stable instrument identity, which is required
+for cumulative-temporality counters).
+
+## Features
+
+- Four instruments: `render_total` (Counter), `render_duration_ms`
+  (Histogram, unit `ms`), `registry_register_total` (Counter),
+  `validation_failure_total` (Counter).
+- Stable meter name: `@suaveplan/email-templates`.
+- `resetEmailTemplatesInstrumentsCacheForTest()` helper to drop the cache
+  between test runs that swap the global `MeterProvider`.
+
+## Usage: Basic
+
+```ts
+import { getEmailTemplatesInstruments } from "@suaveplan/email-templates/otel";
+
+const instruments = getEmailTemplatesInstruments();
+instruments.renderCounter.add(1, { template: "welcome", outcome: "ok" });
+```
+
+## Usage: Advanced
+
+Wire a real metric exporter in test setup and assert the recorded series
+on every render call (the package uses this pattern internally):
+
+```ts
+import {
+  AggregationTemporality,
+  InMemoryMetricExporter,
+  MeterProvider,
+  PeriodicExportingMetricReader,
+} from "@opentelemetry/sdk-metrics";
+import { metrics } from "@opentelemetry/api";
+
+const exporter = new InMemoryMetricExporter(AggregationTemporality.DELTA);
+const reader = new PeriodicExportingMetricReader({ exporter });
+const provider = new MeterProvider({ readers: [reader] });
+metrics.setGlobalMeterProvider(provider);
+
+// ... drive the renderer ...
+
+await reader.forceFlush();
+const series = exporter.getMetrics();
+// assert series contains email_templates.render_total ...
+```
+
+## API Reference
+
+| Symbol                                       | Kind     | Description                                  |
+| -------------------------------------------- | -------- | -------------------------------------------- |
+| `getEmailTemplatesInstruments()`             | function | Returns the cached `EmailTemplatesInstruments`. |
+| `resetEmailTemplatesInstrumentsCacheForTest()` | function | Drops the module-local cache — test-only. |
+| `EmailTemplatesInstruments`                  | type     | The shape of the instrument set.             |
+
+## Implementation Notes
+
+The accessor must remain idempotent. Repeated calls return the same
+object reference; the test corpus asserts that fact because cumulative
+counters lose their backing storage if a meter is re-created mid-flight.
+
+The module never reads `process.env`, `globalThis.window`, or any
+DOM-resident global — it is universal (`engines.bun`, `engines.node`,
+browser) without conditional code paths.