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-db-worker-proxy/src/error-codes/error-codes.md

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+# `error-codes`
+
+<!-- begin:auto-docs -->
+_(no submodules)_
+<!-- end:auto-docs -->
+
+## Purpose
+
+This module owns the `DB_PROXY.*` stable error-code registry for
+`@suaveplan/api-db-worker-proxy`. Every failure that crosses the public
+surface — proxy disposed, transaction lost, cursor stream interrupted,
+unsafe-call attempt against a tenant-scoped wrapper — is raised as a
+`DbProxyError` carrying one of these four codes so consumers can
+discriminate without string-matching messages.
+
+The codes are stable across the package lifecycle: once published, the
+literal value is frozen. New codes are added by extending the
+`defineCodes` tuple; never by renaming.
+
+## Features
+
+- `DB_PROXY_CODES` — frozen registry of fully-qualified code strings.
+- `DbProxyCode` — string-literal union of every registered code.
+- `DbProxyError` — typed subclass of `SuaveplanError<DbProxyCode>`
+  carrying the code, cause chain, and Zod-wire-safe serialisation
+  inherited from `@suaveplan/error`.
+
+## Usage: Basic
+
+```ts
+import {
+    DB_PROXY_CODES,
+    DbProxyError,
+} from "@suaveplan/api-db-worker-proxy/error-codes";
+
+throw new DbProxyError(
+    DB_PROXY_CODES.PROXY_DISPOSED,
+    "cannot call .query() after .close()"
+);
+```
+
+## Usage: Advanced
+
+Branch on the code, not the message. The code is part of the public
+contract; messages are free text and change without notice.
+
+```ts
+try {
+    await proxy.query("SELECT 1");
+} catch (err) {
+    if (err instanceof DbProxyError) {
+        switch (err.code) {
+            case DB_PROXY_CODES.PROXY_DISPOSED:
+                return reopenProxy();
+            case DB_PROXY_CODES.TRANSACTION_LOST:
+                return retryUnit();
+            case DB_PROXY_CODES.STREAM_INTERRUPTED:
+                return reissueCursor();
+            case DB_PROXY_CODES.UNSAFE_NOT_PERMITTED:
+                throw err; // never retry an unsafe path.
+        }
+    }
+    throw err;
+}
+```
+
+## API Reference
+
+- `DB_PROXY_CODES: { UNSAFE_NOT_PERMITTED, TRANSACTION_LOST, STREAM_INTERRUPTED, PROXY_DISPOSED }` — frozen mapping of short names to fully-qualified code strings (`"DB_PROXY.<NAME>"`).
+- `type DbProxyCode = (typeof DB_PROXY_CODES)[keyof typeof DB_PROXY_CODES]`.
+- `class DbProxyError extends SuaveplanError<DbProxyCode>` — constructor `(code, message, options?)` where `options` accepts a `cause` and arbitrary `details`.
+
+## Implementation Notes
+
+The registry is built via `defineCodes("DB_PROXY", [...] as const)` so
+that adding a code without updating both the runtime registry and the
+type union is a compile error. `DbProxyError`'s `name` is set to
+`"DbProxyError"` so structured logs and `errorToEnvelope` round-trip
+correctly across the worker boundary — `@suaveplan/api-worker-rpc`'s
+error-reconstruction layer will reconstruct the class by `code` even
+when the original prototype isn't reachable on the other side.

plugins/document-navigator/docs/api-stack/api/api-db-worker-proxy/src/main-side/main-side.md

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+# `main-side`
+
+<!-- begin:auto-docs -->
+_(no submodules)_
+<!-- end:auto-docs -->
+
+## Purpose
+
+This module exposes `createDbProxyServer(port, db)` — the trusted-side
+endpoint of the worker DB proxy. It mounts an `AdminDatabaseLike`
+adapter on a `MessagePort` and turns every worker-issued RPC frame
+into a real call on the wrapped adapter. The main side is the only
+side that touches the underlying DB driver; the worker code that
+imported `@suaveplan/api-db-worker-proxy/worker-side` never sees a
+real connection, never sees plaintext credentials, and cannot
+fabricate a tenant identity.
+
+The server keeps a registry of live transaction handles and prepared
+statements keyed by id so the worker can drive them across multiple
+round-trips without leaking driver handles into the worker's address
+space.
+
+## Features
+
+- Marshals `query`, `execute`, `prepare`, `transaction`, `cursor`,
+  `engine`, and `close` over `@suaveplan/api-worker-rpc`.
+- Streams cursor rows as `stream-chunk` frames; worker-side break
+  triggers `cancel` which the handler observes via its `AbortSignal`.
+- Bounds transaction lifetimes by port: closing the server (or
+  receiving `goodbye`) raises `TRANSACTION_LOST` on every dangling
+  handle rather than leaking driver state.
+- Exposes diagnostic counters `activeTransactionCount` and
+  `activePreparedCount`.
+
+## Usage: Basic
+
+```ts
+import { createDbProxyServer } from "@suaveplan/api-db-worker-proxy/main-side";
+import { Worker, MessageChannel } from "node:worker_threads";
+
+const channel = new MessageChannel();
+const server = createDbProxyServer(channel.port1, realAdapter);
+
+const worker = new Worker("./worker.js");
+worker.postMessage({ port: channel.port2 }, [channel.port2]);
+```
+
+## Usage: Advanced
+
+When the host needs to scope the adapter per request, pass an
+already-tenant-scoped adapter to a per-request server. The proxy
+itself does NOT rewrite SQL — that responsibility lives in the
+adapter the host hands in here. `wrapTenantScoped` on the worker
+side is purely a type-level facade.
+
+```ts
+const scoped = realAdapter.scopedFor(tenantId); // host responsibility
+const server = createDbProxyServer(port, scoped);
+// shut down at request end:
+server.close("request finished");
+```
+
+## API Reference
+
+- `createDbProxyServer(port: PortLike, db: AdminDatabaseLike): DbProxyServer`.
+- `DbProxyServer.close(reason?: string): void` — closes the server,
+  rolling back live transactions and finalising prepared statements.
+- `DbProxyServer.activeTransactionCount(): number`.
+- `DbProxyServer.activePreparedCount(): number`.
+
+## Implementation Notes
+
+The cursor handler returns an `AsyncGenerator`; `serveWorkerRpc`'s
+streaming path interprets the return as `AsyncIterable<unknown>` and
+emits one `stream-chunk` per yield, then `stream-end ok`. Cancellation
+from the worker comes in as an `AbortSignal.aborted = true` on the
+handler's `signal`; the generator throws `STREAM_INTERRUPTED` which
+the server marshals as `stream-end ok=false` carrying the
+`DB_PROXY.STREAM_INTERRUPTED` code.
+
+Transactions are implemented by holding the adapter's `transaction()`
+promise open until either `tx.commit` or `tx.rollback` fires from the
+worker. Rolling back is signalled by throwing inside the adapter
+callback, which mirrors the adapter's own rollback semantics without
+adding a parallel state machine.

plugins/document-navigator/docs/api-stack/api/api-db-worker-proxy/src/tenant-scoped/tenant-scoped.md

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+# `tenant-scoped`
+
+<!-- begin:auto-docs -->
+_(no submodules)_
+<!-- end:auto-docs -->
+
+## Purpose
+
+This module exposes `wrapTenantScoped(adminProxy, tenantId)` — a
+worker-side type-level facade that re-presents an admin-surface
+`AdminDatabaseLike` as a `TenantScopedDatabaseLike`. The facade
+matters because the two surface types are deliberately
+non-assignable in `@suaveplan/api-types`: a request handler declared
+to accept `TenantScopedDatabaseLike` MUST NOT accidentally receive
+an unscoped admin proxy, and vice versa.
+
+**Tenant scoping is enforced on the main side.** The actual SQL
+rewrite / row-level security / connection routing all live in the
+host's adapter. This wrapper does NOT add policy; it asserts a
+shape so the type system can guarantee the slot in the request
+context has been narrowed to a tenant.
+
+## Features
+
+- Returns a fresh facade object on every call so the same admin
+  proxy can back many concurrent request scopes.
+- Exposes `tenantId` on the returned object for audit logging.
+- Preserves the optional `prepare` / `transaction` capabilities only
+  if the admin proxy advertised them; absent capabilities throw
+  `DB_PROXY.UNSAFE_NOT_PERMITTED`.
+- `close` is intentionally omitted because
+  `TenantScopedDatabaseLike` does not expose it — the admin proxy
+  retains lifecycle ownership.
+
+## Usage: Basic
+
+```ts
+import { wrapTenantScoped } from "@suaveplan/api-db-worker-proxy/tenant-scoped";
+import type { TenantId } from "@suaveplan/api-types/tenant";
+
+const tenantId = "acme" as TenantId;
+const scoped = wrapTenantScoped(adminProxy, tenantId);
+const rows = await scoped.query("SELECT * FROM invoices");
+```
+
+## Usage: Advanced
+
+Use the facade inside a request middleware that materialises
+`RequestContext.db`. The middleware constructs the wrapper from the
+already-resolved `tenantId` so route handlers only ever see the
+tenant-scoped type.
+
+```ts
+function attachDb(adminProxy: AdminDatabaseLike) {
+    return async (c: Context, next: Next): Promise<void> => {
+        const tenantId = c.get("tenantId") as TenantId;
+        const scoped = wrapTenantScoped(adminProxy, tenantId);
+        c.set("db", scoped);
+        await next();
+    };
+}
+```
+
+## API Reference
+
+- `wrapTenantScoped(adminProxy: AdminDatabaseLike, tenantId: TenantId): TenantScopedDatabaseLike`.
+- Throws `DB_PROXY.UNSAFE_NOT_PERMITTED` from `prepare` / `transaction`
+  when the underlying admin proxy doesn't expose that capability.
+
+## Implementation Notes
+
+The wrapper rebinds `prepare` and `transaction` so the underlying
+admin proxy's `this`-context survives the indirection (the methods
+are looked up off the proxy each call, not captured eagerly, so
+admin-side disposal is observed on the next call rather than at wrap
+time).
+
+The `tenantId` field is set on the returned object purely so audit
+loggers and `RequestContext` consumers can read it directly. The
+field name and type match `TenantScopedDatabaseLike.tenantId`
+exactly; both are `TenantId` (a branded string).

plugins/document-navigator/docs/api-stack/api/api-db-worker-proxy/src/testing/testing.md

@@ -0,0 +1,97 @@
+# `testing`
+
+<!-- begin:auto-docs -->
+_(no submodules)_
+<!-- end:auto-docs -->
+
+## Purpose
+
+This module provides the in-memory test harness for
+`@suaveplan/api-db-worker-proxy`. It exposes `createInMemoryAdminDb`
+— a deterministic `AdminDatabaseLike` backed by a `Map` — and
+`createDbProxyHarness`, which pairs that adapter with a real
+`MessageChannel`, a `createDbProxyServer` on one port, and a
+`createDbProxyClient` on the other. Tests can drive the full
+client-port-server-adapter chain end-to-end without a real DB and
+without any mocking framework.
+
+The harness exists in `src/testing/` (rather than `tests/`) so it
+can be imported by downstream Stage-4 adapter packages from the
+package's `"./testing"` subpath export.
+
+## Features
+
+- `createInMemoryAdminDb({ engine?, seed?, cursorDelayMs? })` — a
+  full `AdminDatabaseLike` implementation including `prepare`,
+  `transaction`, and a synthetic `SELECT-CURSOR *` that returns an
+  `AsyncIterable<MemoryRow>` for cursor streaming tests.
+- `createDbProxyHarness(opts)` — bundles adapter + ports + server +
+  client into one disposable handle.
+- Tiny command DSL (`INSERT <id>`, `DELETE <id>`, `SELECT *`,
+  `SELECT-CURSOR *`, `COUNT`, `SELECT-SCALAR`, `THROW`) chosen so
+  every code path in the proxy can be exercised without parsing real
+  SQL.
+
+## Usage: Basic
+
+```ts
+import { createDbProxyHarness } from "@suaveplan/api-db-worker-proxy/testing";
+
+const h = createDbProxyHarness({ seed: [["a", { v: 1 }]] });
+try {
+    expect(await h.client.query("SELECT *")).toEqual([{ v: 1 }]);
+} finally {
+    await h.client.close();
+    h.close();
+}
+```
+
+## Usage: Advanced
+
+To assert that cursor cancellation propagates, set a per-row delay
+on the in-memory cursor and abort partway through:
+
+```ts
+const h = createDbProxyHarness({
+    seed: Array.from({ length: 100 }, (_, i) => [String(i), { i }]),
+    cursorDelayMs: 5,
+});
+try {
+    const ac = new AbortController();
+    let n = 0;
+    for await (const _row of h.client.cursor("SELECT-CURSOR *", undefined, {
+        signal: ac.signal,
+    })) {
+        if (++n >= 3) {
+            ac.abort();
+            break;
+        }
+    }
+    expect(n).toBe(3);
+} finally {
+    await h.client.close();
+    h.close();
+}
+```
+
+## API Reference
+
+- `createInMemoryAdminDb(opts?): InMemoryAdminDb` — `AdminDatabaseLike`
+  plus `rows: ReadonlyMap<string, MemoryRow>` and `closed(): boolean`
+  for assertions.
+- `createDbProxyHarness(opts?): DbProxyHarness` — `{ db, server,
+  client, ports, close() }`.
+- `InMemoryAdminDbOptions` — `{ engine?, seed?, cursorDelayMs? }`.
+
+## Implementation Notes
+
+The in-memory adapter ignores parameter placeholders for `INSERT` /
+`DELETE` and instead encodes the row key in the SQL string. This is
+intentional — the harness exists to exercise the proxy plumbing, not
+to validate a real query language. Concrete adapters (Stage 4) ship
+their own conformance suites under their own engine semantics.
+
+The harness's `close()` does NOT call `client.close()` so tests can
+choose between observing graceful close (`await client.close()`) and
+abrupt disconnect (`client.dispose()`, then `harness.close()`). Both
+paths are first-class.

plugins/document-navigator/docs/api-stack/api/api-db-worker-proxy/src/worker-side/worker-side.md

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+# `worker-side`
+
+<!-- begin:auto-docs -->
+_(no submodules)_
+<!-- end:auto-docs -->
+
+## Purpose
+
+This module exposes `createDbProxyClient(port, { engine })` — the
+untrusted-side endpoint of the worker DB proxy. It returns an
+`AdminDatabaseLike`-shaped object whose methods marshal across a
+`MessagePort` to the main side's `createDbProxyServer`. Worker plugin
+code uses the returned proxy exactly as it would use a direct adapter
+— `await db.query(...)`, `await db.transaction(async (tx) => ...)` —
+without knowing the real connection lives in another process.
+
+The factory is synchronous because `AdminDatabaseLike.engine` is a
+synchronous getter; the caller supplies the engine identifier
+up-front (the host knows which engine it has provisioned, so this is
+free information).
+
+## Features
+
+- Full `AdminDatabaseLike` surface: `query`, `execute`, `prepare`,
+  `transaction`, `close`, `engine`.
+- Bonus `cursor(sql, params)` returns an `AsyncIterable<unknown>`
+  backed by `@suaveplan/api-worker-rpc` streaming; consumer `break`
+  cancels the main-side cursor.
+- `transaction(fn)` auto-commits on resolve and auto-rolls-back on
+  reject; the inner `tx` handle becomes invalid after the callback
+  resolves and any subsequent call throws `DB_PROXY.TRANSACTION_LOST`.
+- `dispose()` (alongside the interface's `close`) tears down the
+  underlying port without invoking the main-side `close()` handler.
+
+## Usage: Basic
+
+```ts
+import { createDbProxyClient } from "@suaveplan/api-db-worker-proxy/worker-side";
+
+const db = createDbProxyClient(port, { engine: "sqlite" });
+const rows = await db.query<MyRow[]>("SELECT * FROM users");
+```
+
+## Usage: Advanced
+
+Streaming a large cursor without buffering everything in worker
+memory:
+
+```ts
+const ac = new AbortController();
+let seen = 0;
+for await (const row of db.cursor("SELECT-CURSOR *", undefined, {
+    signal: ac.signal,
+})) {
+    if (++seen >= 100) {
+        ac.abort();
+        break;
+    }
+    process(row);
+}
+```
+
+`db.transaction` wires commit/rollback through the same port, so the
+main-side transaction is bound to the worker's logical scope:
+
+```ts
+await db.transaction(async (tx) => {
+    await tx.execute("INSERT user-1", { name: "Alice" });
+    await tx.execute("INSERT user-2", { name: "Bob" });
+}); // auto-commit
+```
+
+## API Reference
+
+- `createDbProxyClient(port, opts): DbProxyClient` — extends
+  `AdminDatabaseLike` with `cursor(...)` and `dispose()`.
+- `DbProxyClientOptions.engine: DatabaseEngine` — supplied by host.
+- `DbProxyClient.cursor(sql, params?, { signal? }): AsyncIterable<unknown>`.
+- `DbProxyClient.dispose(): void` — close port without server round-trip.
+
+## Implementation Notes
+
+Cursor iteration wraps `streamRequest` from
+`@suaveplan/api-worker-rpc` so the same backpressure policy (default
+64-frame bounded queue) governs row delivery. The wrapper translates
+any non-`DbProxyError` exception coming up from the stream into
+`DB_PROXY.STREAM_INTERRUPTED` so consumers can branch uniformly on
+the proxy's error namespace.
+
+`transaction(fn)` uses a closure-flag (`inScope`) to gate every `tx`
+method; after the callback resolves and the proxy issues `tx.commit`,
+the flag flips and any leaked reference to `tx` throws
+`DB_PROXY.TRANSACTION_LOST`. The auto-commit is suppressed if the
+callback already invoked `tx.commit` itself (the second commit
+would otherwise raise `TRANSACTION_LOST` from the main side, which
+this layer catches and silences).