docs(#2627): crate READMEs for the harness column (hive-agent, hive-agent-mcp, hive-agent-wake, hive-bash-mcp)

hive-bash-mcp/Cargo.toml

@@ -2,6 +2,7 @@
 name = "hive-bash-mcp"
 edition.workspace = true
 version.workspace = true
+readme = "README.md"
 
 [lints]
 workspace = true

hive-bash-mcp/README.md

@@ -0,0 +1,36 @@
+# hive-bash-mcp
+
+Per-agent background bash-task runner: a long-running daemon
+(`hive-bash-daemon`) plus the thin stdio MCP bridge
+(`hive-bash-mcp`) claude spawns each turn to talk to it. This is what
+backs the `bash_run` / `bash_status` tools agents use to kick off
+long-lived shell commands (builds, test suites, anything that
+shouldn't block a turn) and check on them later.
+
+## When to use it
+
+Look here when changing how background bash tasks are spawned,
+tracked, or surfaced. The daemon owns all subprocess lifecycle
+(`sh -c` spawn, completion monitoring, task state files under
+`harness/bash-tasks/`) and pushes task-completion todos onto the
+harness's in-agent socket so they show up in `get_loose_ends`. The
+bridge binary is deliberately dumb: no subprocess management, just a
+unix-socket round-trip per tool call, so it cold-starts in
+milliseconds every turn.
+
+## Shape
+
+Two bins from one shared lib (`src/lib.rs`):
+
+- **`hive-bash-daemon`** (`src/main.rs`) — the long-running daemon.
+  `runner.rs` is the spawn/monitor loop and pushes todos on task
+  transitions; `socket.rs` serves the daemon's own unix socket for
+  tool-call requests from the bridge.
+- **`hive-bash-mcp`** (`src/bin/mcp.rs`) — the stdio MCP server claude
+  spawns per turn. Forwards every tool call to the daemon over the
+  socket via `protocol.rs`'s `DaemonRequest`/`DaemonResponse` and
+  returns the result.
+
+Supporting modules: **`paths.rs`** (daemon socket + agent-socket
+resolution), **`stats.rs`** (the `bash_commands` favorite-tool stat
+recorded into turn-stats.sqlite).