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/api-stack/api/api-router-hono/src/middleware-adapter/middleware-adapter.md

@@ -0,0 +1,65 @@
+# `middleware-adapter` — Middleware ⇄ Hono MiddlewareHandler bridge
+
+<!-- begin:auto-docs -->
+_(no submodules)_
+<!-- end:auto-docs -->
+
+## Purpose
+
+This module bidirectionally bridges the onion-model `Middleware` type from `@suaveplan/api-router` and Hono's native `MiddlewareHandler`. The bridge is what lets a `Router` adapter installed on top of a Hono app participate in the same per-request pipeline — inbound headers become `RouterRequest`, outbound builder results become Web `Response` objects, and downstream Hono middlewares observe the `next()` boundary as their own.
+
+The conversion is intentionally one-directional in effect: `toHonoMiddleware` runs the suaveplan middleware ahead of Hono's downstream chain, while `fromHonoMiddleware` defers strictly to the `next()` because Hono context cannot be safely synthesised outside a real dispatch. Real Hono middlewares get installed via `getHonoApp().use(...)` directly.
+
+## Features
+
+- `toHonoMiddleware(mw)` — adapts a `Middleware` to a `MiddlewareHandler` Hono can install.
+- `fromHonoMiddleware(handler)` — produces a `Middleware` that defers to the chain; throws `ROUTER_HONO.INVALID_HONO_PEER` for non-functions.
+- Header/query reflection from `c.req.raw` to `MapHeaders` so handlers run against the canonical suaveplan
+- Wraps Hono-internal throws in `RouterHonoError` with code `HONO_INTERNAL_ERROR` and a cause-chain.
+
+## Usage: Basic
+
+```ts
+import { toHonoMiddleware } from "@suaveplan/api-router-hono/middleware-adapter";
+import type { Middleware } from "@suaveplan/api-router";
+import { Hono } from "hono";
+
+const trace: Middleware = async (req, next) => {
+    console.log(req.requestId);
+    return next();
+};
+
+const app = new Hono();
+app.use("*", toHonoMiddleware(trace));
+```
+
+## Usage: Advanced
+
+```ts
+import {
+    fromHonoMiddleware,
+    toHonoMiddleware,
+} from "@suaveplan/api-router-hono/middleware-adapter";
+import { createHonoRouter } from "@suaveplan/api-router-hono/adapter";
+
+const router = createHonoRouter();
+
+router.use(async (req, next) => {
+    const res = await next();
+    return { ...res, headers: { ...res.headers, "x-trace": req.requestId } };
+});
+
+const app = router.getHonoApp();
+app.use("*", toHonoMiddleware(async (_req, next) => next()));
+```
+
+## API Reference
+
+- `toHonoMiddleware(mw: Middleware): MiddlewareHandler` — wraps a suaveplan middleware.
+- `fromHonoMiddleware(handler: MiddlewareHandler): Middleware` — wraps a Hono middleware.
+
+Both helpers preserve the `RouterError` / `RouterHonoError` cause chains so observability stays end-to-end.
+
+## Implementation Notes
+
+`contextToRouterRequest` reads `x-tenant-id` and `x-request-id` headers (case-insensitive) to populate the corresponding fields. Both default to safe stand-ins (`"default"` tenant, time-derived request id) so unit tests bypass middleware setup. `routerResponseToWebResponse` JSON-stringifies non-string bodies and sets `content-type: application/json` when no body content-type is already present.