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/testkit/testing/testing-e2e/src/observability/instrumented.md

@@ -0,0 +1,66 @@
+# observability/instrumented
+
+<!-- begin:auto-docs -->
+_(no submodules)_
+<!-- end:auto-docs -->
+## Purpose
+
+`instrumented` is the gated OpenTelemetry wrapper for `@suaveplan/testing-e2e` helpers and fixtures. When `TESTING_E2E_OTEL_ENABLED` is set, wrapped calls emit counters for invocations, histograms for durations, and span events for failures — giving a Playwright test run the same structured telemetry as a production service. When the flag is off, `instrumented` returns the original function reference unchanged so test-run cost is identical to the unwrapped case.
+
+## Features
+
+- Gated at module import via `TESTING_E2E_OTEL_ENABLED` — no per-call env reads
+- Uses `@opentelemetry/api` only (no SDK) — consumers wire exporters at bootstrap
+- Preserves signature and return type of the wrapped function
+- Handles sync and async fn forms, including rejection
+- Zero overhead when disabled (identity pass-through)
+
+## Usage: Basic Example
+
+```ts
+import { instrumented } from "@suaveplan/testing-e2e/observability";
+
+const navigate = instrumented("testing_e2e.navigate", async (page: Page, url: string) => {
+    await page.goto(url);
+});
+```
+
+## Usage: Advanced Example
+
+```ts
+import { instrumented } from "@suaveplan/testing-e2e/observability";
+
+class DashboardPage {
+    public gotoInstrumented = instrumented(
+        "testing_e2e.page.dashboard.goto",
+        async (page: Page) => {
+            await page.goto("/dashboard");
+            await page.waitForLoadState("domcontentloaded");
+        }
+    );
+
+    public filterInstrumented = instrumented(
+        "testing_e2e.page.dashboard.filter",
+        async (page: Page, query: string) => {
+            await page.fill('input[name="q"]', query);
+            await page.press('input[name="q"]', "Enter");
+        }
+    );
+}
+```
+
+## API Reference
+
+### `instrumented<TFn>(name, fn): TFn`
+
+- `name` — metric name suffix; the full name becomes `testing_e2e.<name>.count` / `duration_ms` / `errors`
+- `fn` — any function to wrap
+- Returns `TFn` with the same signature; instrumented only when the env flag is set
+
+### Environment gating
+
+`TESTING_E2E_OTEL_ENABLED` must equal `"1"` or `"true"` at module-import time.
+
+## Implementation Notes
+
+The env check runs once at module import — flipping the variable mid-run has no effect, which avoids per-call reads in the hot path. With instrumentation enabled but no OTel SDK registered, `@opentelemetry/api` returns no-op tracers and meters, so the overhead is a single no-op counter increment. The disabled branch returns the original function reference, so V8 inlines it as if the wrapper was never there.