recv: fold batch drain into recv(max) — one tool, uniform list response

CLAUDE.md

@@ -183,29 +183,32 @@ read them à la carte.
 In-flight or recent context that hasn't earned a section yet.
 Prune freely.
 
-- **Just landed:** inbox batching via `recv_batch(max)`. New
-  MCP tool on both agent + manager surfaces pops up to `max`
-  pending messages in a single round-trip (server-side cap
-  32, `max = 0` short-circuits). Same delivery + ack
-  bookkeeping as `recv`: every popped row is marked
-  `delivered_at = NOW`, tracked on the per-recipient
-  `unacked_ids` list (so the next `AckTurn` closes them out),
-  and tagged `redelivered: true` if it was resurfaced by
-  `RequeueInflight`. Wake prompt's pending-inbox hint
-  rewritten to recommend `recv_batch(max: N)` instead of N
-  consecutive `recv`s. Wire: new
-  `AgentRequest::RecvBatch { max }` /
-  `AgentResponse::Batch { messages: Vec<DeliveredMessage> }`
-  (+ manager mirror) and a new `DeliveredMessage` struct in
-  `hive-sh4re` shared by both. `format_recv_batch` on the
-  mcp side renders the popped list with per-message
-  redelivery banners + `---` separators; empty batch
-  collapses to "(empty)" like single `recv`. 4 new broker
-  tests cover FIFO + cap, empty-when-idle, zero-max
-  short-circuit, and redelivered-flag propagation. Closes
-  the "inbox batching hint" item from the ergonomics
-  wishlist — the hint that was already in `format_wake_prompt`
-  is now actionable in one tool call instead of N.
+- **Just landed:** inbox batching unified into `recv(max?)`.
+  No separate `recv_batch` tool — the existing `recv` tool
+  grew an optional `max: u32` arg (default 1, server-side
+  cap 32) so a single round-trip drains up to N popped rows
+  with the same delivery + ack bookkeeping per row
+  (`delivered_at = NOW`, `unacked_ids` list, redelivered
+  tag from `requeue_inflight`). `wait_seconds` still applies
+  to the FIRST message; once one lands the call drains up
+  to `max` in total — long-poll + drain compose. Wake
+  prompt's pending-inbox hint points at `recv(max: N)`.
+  Wire shape: `AgentRequest::Recv { wait_seconds, max }`
+  (added `max`), `AgentResponse::Messages { messages:
+  Vec<DeliveredMessage> }` (collapsed the old
+  `Message` + `Empty` + `Batch` trio into one always-list
+  variant — empty vec = idle). `DeliveredMessage` is a flat
+  shared struct in `hive-sh4re`. `format_recv` renders
+  single = the historical `from: X\n\nbody` block, multi =
+  `popped N message(s)` header with `---` separators +
+  per-message redelivery banners; empty = "(empty)". Broker
+  primitive: dropped the singular `recv`, kept just
+  `recv_batch(recipient, max)` and `recv_blocking_batch`
+  (which long-polls then drains via `recv_batch`). 4 new
+  broker tests on top of the existing 7 (recv_batch_*
+  family). Closes the "inbox batching hint" item from the
+  ergonomics wishlist with one tool instead of two; lower
+  context bloat in claude's prompt.
 - **Just landed:** lease-style message delivery / no-drop
   on turn fail. The `messages` table gained an `acked_at`
   column (idempotent ALTER + backfill = `delivered_at` so