refactor(crates/rt): Stage 2 runtime improvements

- http: connection, listener, request, response, route updates
- pg: protocol improvements
- runtime: eventfd, netpoll (epoll/io_uring), scheduler, signalfd, timerfd
- shard: cross-shard job improvements
- wal: replay and recovery fixes

crates/rt/src/http/connection.rs

@@ -10,7 +10,7 @@
 //!     any buffered pipelined request); `Connection: close` goes to Done.
 //!   Done    → loop closes the fd.
 //!
-//! Adapted from `reference/crates/wo-http/src/connection.rs`. The owning
+//! Adapted from `.dev/reference/crates/wo-http/src/connection.rs`. The owning
 //! [`EventLoop`] supplies `read`/`write` readiness via edge-triggered
 //! `epoll`; this struct is the per-fd part of the state.
 //!

crates/rt/src/http/listener.rs

@@ -1,6 +1,6 @@
 //! Non-blocking TCP listener — `socket(2)` + `bind(2)` + `listen(2)` + `accept4(2)`.
 //!
-//! Adapted from `reference/crates/wo-http/src/listener.rs`. The v1 hand-rolled
+//! Adapted from `.dev/reference/crates/wo-http/src/listener.rs`. The v1 hand-rolled
 //! IPv4 parser had a byte-order bug for non-localhost addresses; here we
 //! defer to `std::net::SocketAddr` (stdlib, no extra crate) and convert the
 //! resulting octets to a `sockaddr_in` correctly.

crates/rt/src/http/request.rs

@@ -1,6 +1,6 @@
 //! Incremental HTTP/1.1 request parser.
 //!
-//! Adapted from `reference/crates/wo-http/src/request.rs`. v1 only parsed
+//! Adapted from `.dev/reference/crates/wo-http/src/request.rs`. v1 only parsed
 //! request headers (the v1 blog is read-only HTML). The phase-04 cutover
 //! needs JSON request bodies, so this parser also drains a
 //! `Content-Length`-delimited body. Chunked transfer encoding is not

crates/rt/src/http/response.rs

@@ -1,6 +1,6 @@
 //! HTTP/1.1 response builder + serializer.
 //!
-//! Adapted from `reference/crates/wo-http/src/response.rs`. Adds:
+//! Adapted from `.dev/reference/crates/wo-http/src/response.rs`. Adds:
 //!   * `Status` constants for the codes the REST samples assert on
 //!     (200/201/204/400/404/405/500/501).
 //!   * `Response::json(&serde_json::Value)` matching the cutover-handler

crates/rt/src/http/route.rs

@@ -1,6 +1,6 @@
 //! Method + URL pattern → handler dispatch.
 //!
-//! Combined adaptation of `reference/crates/wo-route/src/{router,pattern}.rs`.
+//! Combined adaptation of `.dev/reference/crates/wo-route/src/{router,pattern}.rs`.
 //! Handler shape is `Fn(&Request, &RouteParams) -> Response`, captured as a
 //! boxed closure so each route closes over its own state (typically an
 //! `Arc<Mutex<Engine>>` — see `crates/rt/src/server.rs`).

crates/rt/src/pg.rs

@@ -14,7 +14,7 @@
 //!   * literal/identifier escaping for SQL the mirror generates
 //!
 //! Protocol reference: PostgreSQL docs “Frontend/Backend Protocol” and
-//! `reference/postgresql/src/include/libpq/` (research symlink).
+//! `.dev/reference/postgresql/src/include/libpq/` (research symlink).
 //!
 //! Blocking I/O is deliberate: the only caller is the dedicated `wo-pg`
 //! mirror thread (plan 16b) — never a shard worker.

crates/rt/src/runtime/eventfd.rs

@@ -4,7 +4,7 @@
 //! event loop to come back and run something writes a `1` to the eventfd,
 //! which becomes readable on the loop's next `wait_once`.
 //!
-//! Ported from `reference/crates/wo-event/src/eventfd.rs` with an added
+//! Ported from `.dev/reference/crates/wo-event/src/eventfd.rs` with an added
 //! `AsRawFd` impl so callers can drop the fd straight into `EventLoop`.
 
 use std::io;

crates/rt/src/runtime/netpoll_epoll.rs

@@ -1,6 +1,6 @@
 //! `epoll`-backed event loop. Single-threaded, edge-triggered.
 //!
-//! Ported from `reference/crates/wo-event/src/epoll.rs`. Differences:
+//! Ported from `.dev/reference/crates/wo-event/src/epoll.rs`. Differences:
 //!   * `Token` is a newtype rather than a `u64` alias.
 //!   * `Interest` is a struct exposing `READABLE`, `WRITABLE`, `READ_WRITE`
 //!     constants, matching the API in `docs/plan/02-event-loop-epoll.md`.

crates/rt/src/runtime/netpoll_io_uring.rs

@@ -1,5 +1,5 @@
 //! Raw io_uring — no liburing, kernel ABI structs defined by hand, exactly
-//! the sequence proven in C (`prototypes/wo-rt-c/wo-rt.c` ring_init/enter;
+//! the sequence proven in C (`runtime/wo-rt.c` ring_init/enter;
 //! card: `docs/plan/exploration/linux/07-io_uring.md`).
 //!
 //! Scope (this phase): the **storage ring** for per-shard group commit —

crates/rt/src/runtime/scheduler.rs

@@ -10,7 +10,7 @@
 //! Per plan 09a, **engine state stays globally shared** (`Arc<Mutex<Engine>>`
 //! inside the per-thread `Router`s) — one thing at a time; the sharded engine
 //! is 09b. The C proving ground for this exact sequence is
-//! `prototypes/wo-rt-c` phase A (see `docs/plan/exploration/c-runtime/`).
+//! `runtime` phase A (see `docs/plan/exploration/c-runtime/`).
 //!
 //! Shutdown: signals are blocked in `main` before any worker spawns (the
 //! mask is inherited), so only worker 0 — which owns the `signalfd` — ever

crates/rt/src/runtime/signalfd.rs

@@ -5,7 +5,7 @@
 //!
 //! Blocks the captured signals in the calling thread's mask, so the
 //! kernel routes them to the signalfd instead of running default handlers.
-//! Ported from `reference/crates/wo-event/src/signalfd.rs`.
+//! Ported from `.dev/reference/crates/wo-event/src/signalfd.rs`.
 
 use std::io;
 use std::os::unix::io::{AsRawFd, RawFd};

crates/rt/src/runtime/timerfd.rs

@@ -4,7 +4,7 @@
 //! fd becomes readable when the timer expires; reading drains the
 //! expiration count.
 //!
-//! Ported from `reference/crates/wo-event/src/timerfd.rs`. Adds `oneshot`
+//! Ported from `.dev/reference/crates/wo-event/src/timerfd.rs`. Adds `oneshot`
 //! and `periodic` constructors that match the API in the phase-02 plan.
 
 use std::io;

crates/rt/src/shard.rs

@@ -16,7 +16,7 @@
 //! coordination. Creates are always local (the receiving shard mints from
 //! its own stride); reads/updates/deletes hop at most once; lists fan out
 //! to every shard and merge. The C proving ground for the wake mechanism is
-//! `prototypes/wo-rt-c` (eventfd broadcast); the mailbox-per-thread design
+//! `runtime` (eventfd broadcast); the mailbox-per-thread design
 //! is plan 09 decision 2 and 09d's one-message-per-thread fan-out shape.
 
 use std::cell::RefCell;

crates/rt/src/wal.rs

@@ -1,6 +1,6 @@
 //! Per-shard write-ahead log — plan 09c (`docs/plan/09-concurrency-scaleout.md`)
 //! + the durability core of plan 11, ported from the proven C sequence
-//! (`prototypes/wo-rt-c` phases D/E, `docs/plan/exploration/c-runtime/00-plan.md`).
+//! (`runtime` phases D/E, `docs/plan/exploration/c-runtime/00-plan.md`).
 //!
 //! One `shard-<t>.rwal` per worker. Frame format (identical shape to the C
 //! prototype): `u32 len | u32 crc32(payload) | payload | u32 COMMIT` — a