relayburn-cli: burn ingest + burn mcp-server (#248 D8, closes #210)

CHANGELOG.md

@@ -4,6 +4,7 @@ Cross-package release notes for relayburn. Package changelogs contain package-le
 
 ## [Unreleased]
 
+- `relayburn-cli` (Rust): wire `burn ingest` (no-flag scan, `--watch` poll loop, `--hook claude --quiet`) and `burn mcp-server` stdio subcommand exposing `burn__sessionCost`; closes #210. (#248 D8)
 - `relayburn-cli` (Rust): wire codex `HarnessAdapter` via `pending_stamp::adapter_static` factory; registered in `RUNTIME_ADAPTERS`. (#248 D6)
 - `relayburn-cli` (Rust): wire `burn compare` as a presenter over `relayburn_sdk::analyze::compare` building blocks (`build_compare_table` + the per-turn fidelity gate), matching the TS CLI flag set (positional comma-separated model list, `--include-partial` / `--fidelity` / `--since` / `--project` / `--session` / `--min-sample` / `--csv` / `--no-archive`) and producing byte-equivalent stdout for the cli-golden `compare` / `compare-json` invocations. (#248 D3)
 - `relayburn-cli` (Rust): port `burn overhead` and `burn overhead trim` as thin presenters over `relayburn_sdk::overhead` / `::overhead_trim`. Output (human + `--json`) is byte-equivalent with the TS CLI. (#248 D2)

crates/relayburn-cli/Cargo.toml

@@ -77,7 +77,11 @@ thiserror = { workspace = true }
 # bodies via a current-thread runtime.
 async-trait = "0.1"
 phf = { version = "0.11", features = ["macros"] }
-tokio = { workspace = true, features = ["sync", "rt"] }
+# `signal` is needed for the `burn ingest --watch` SIGINT/SIGTERM trap
+# (#248 D8); the watch loop blocks the foreground until a stop signal
+# comes in. `rt` drives the current-thread runtime that wraps the SDK's
+# async ingest verb from otherwise-sync presenter bodies.
+tokio = { workspace = true, features = ["sync", "rt", "signal"] }
 
 # `IndexMap` preserves first-seen iteration order, which matters for the
 # Wave 2 read-path commands so their grouped output (`summary --by-model`,

crates/relayburn-cli/src/cli.rs

@@ -115,12 +115,77 @@ pub enum Command {
     State(StateArgs),
 
     /// Scan harness session stores and append new turns to the ledger.
-    Ingest,
+    Ingest(IngestArgs),
 
     /// Stdio MCP server exposing read-only ledger queries for
     /// in-session self-query.
     #[command(name = "mcp-server")]
-    McpServer,
+    McpServer(McpServerArgs),
+}
+
+/// Per-command flags for `burn ingest`. Mirrors the TS surface in
+/// `packages/cli/src/commands/ingest.ts` so flag muscle memory carries
+/// across.
+///
+/// Three modes, exactly one applies per invocation:
+///
+/// - No flags: scan all known session stores once and exit.
+/// - `--watch` (optionally with `--interval <MS>`): foreground poll loop
+///   driven by [`relayburn_sdk::start_watch_loop`].
+/// - `--hook <HARNESS> [--quiet]`: stdin-driven hook entrypoint. Today
+///   only `--hook claude` is supported; the `--quiet` flag suppresses
+///   non-error stderr breadcrumbs so it is safe to call from every
+///   Claude Code hook.
+///
+/// `--watch` and `--hook` are mutually exclusive; the presenter rejects
+/// the combination at runtime with exit 2 (matching TS).
+#[derive(Debug, Clone, ClapArgs)]
+pub struct IngestArgs {
+    /// Stay running and poll session stores at `--interval` ms.
+    /// Mutually exclusive with `--hook`.
+    #[arg(long)]
+    pub watch: bool,
+
+    /// Poll interval for `--watch`, in milliseconds. Defaults to 1000.
+    /// Ignored without `--watch`.
+    #[arg(long, value_name = "MS")]
+    pub interval: Option<u64>,
+
+    /// Read a harness-specific hook payload from stdin and ingest the
+    /// transcript it references. Today only `claude` is supported.
+    /// Mutually exclusive with `--watch`.
+    #[arg(long, value_name = "HARNESS")]
+    pub hook: Option<String>,
+
+    /// Suppress non-error stderr breadcrumbs. Used by hook callers so
+    /// the surrounding tool invocation isn't blocked by a noisy
+    /// pipeline. Only meaningful with `--hook`; clap rejects `--quiet`
+    /// on its own (or with `--watch`) so a typo can't silently no-op.
+    #[arg(long, requires = "hook")]
+    pub quiet: bool,
+}
+
+/// Per-command flags for `burn mcp-server`. The stdio MCP server speaks
+/// JSON-RPC 2.0 line-delimited frames over stdin/stdout and exposes the
+/// `burn__sessionCost` read-only tool. Closes #210.
+///
+/// Global `--ledger-path` (on [`Args`]) is consulted as the SDK ledger
+/// home. `--session-id` registers a default session id so MCP clients
+/// that omit `sessionId` in `tools/call` get a useful answer (the
+/// running agent's own session).
+#[derive(Debug, Clone, ClapArgs)]
+pub struct McpServerArgs {
+    /// Default sessionId to use when `tools/call burn__sessionCost`
+    /// omits the argument. Lets the host wrap the server with the
+    /// running agent's own session id so the agent can self-query
+    /// without knowing it.
+    #[arg(long = "session-id", value_name = "ID")]
+    pub session_id: Option<String>,
+
+    /// Emit protocol-level diagnostics to stderr. Off by default so a
+    /// well-behaved client doesn't see unexpected noise on the channel.
+    #[arg(long)]
+    pub debug: bool,
 }
 
 /// Per-command flag set for `burn compare`. Mirrors