claw-cargo: map cargo profile name to actual target dir

Cargo aliases the `dev`/`test` profiles to `target/debug/` and
`release`/`bench` to `target/release/`. claw-cargo was using the
profile name verbatim as the subdirectory, so with the default
`profile = "dev"` config it looked for `target/dev/` — a directory
that never exists — and silently skipped the capture+upload step
after a successful cold build.

Symptom in the field (pilot deploy on tank, 2026-07-12):

    Finished `dev` profile [unoptimized + debuginfo] target(s) in 12.22s
    cargo build finished in 12.2461178s
    target dir ./target/dev does not exist after cargo build — skipping upload

Fix: `target_subdir_for(profile)` maps aliases to their real dirs;
custom profile names pass through unchanged. Applied in `cmd_build`
and `cmd_prefetch`. Cheap unit test guards the mapping so the same
bug can't come back.

claw-store/src/claw_cargo.rs

@@ -365,7 +365,7 @@ async fn cmd_status(args: PeerArgs) -> Result<()> {
 
 async fn cmd_prefetch(args: PrefetchArgs) -> Result<()> {
     let (workspace, resolved, fp) = setup_peer(&args.peer)?;
-    let target_dir = workspace.join("target").join(&resolved.profile);
+    let target_dir = workspace.join("target").join(target_subdir_for(&resolved.profile));
 
     let (client, conn) = connect_peer(&resolved).await?;
 
@@ -485,7 +485,7 @@ async fn resolve_pin(
 
 async fn cmd_build(args: BuildArgs) -> Result<()> {
     let (workspace, resolved, fp) = setup_peer(&args.peer)?;
-    let target_dir = workspace.join("target").join(&resolved.profile);
+    let target_dir = workspace.join("target").join(target_subdir_for(&resolved.profile));
     tracing::info!("fingerprint {}", fp);
 
     let (client, conn) = connect_peer(&resolved).await?;
@@ -911,6 +911,18 @@ async fn cmd_prewarm(args: PrewarmArgs) -> Result<()> {
     Ok(())
 }
 
+/// Map a cargo profile name to the directory under `target/` cargo
+/// actually writes to. Cargo aliases `dev`/`test` to `debug/` and
+/// `release`/`bench` to `release/`; every other (custom) profile
+/// gets a directory of the same name.
+fn target_subdir_for(profile: &str) -> &str {
+    match profile {
+        "dev" | "test" => "debug",
+        "release" | "bench" => "release",
+        other => other,
+    }
+}
+
 fn run_cargo(
     workspace: &Path,
     profile: &str,
@@ -928,3 +940,24 @@ fn run_cargo(
     let status = cmd.status().context("spawning cargo build")?;
     Ok(status)
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn target_subdir_matches_cargo_layout() {
+        // Cargo's built-in profile aliases: dev + test both compile
+        // into `target/debug/`; release + bench compile into
+        // `target/release/`. Custom profiles get a dir of the same
+        // name. Getting this wrong silently skips the capture step
+        // ("target dir does not exist after cargo build") — the exact
+        // failure mode we hit in the field on the first pilot run.
+        assert_eq!(target_subdir_for("dev"), "debug");
+        assert_eq!(target_subdir_for("test"), "debug");
+        assert_eq!(target_subdir_for("release"), "release");
+        assert_eq!(target_subdir_for("bench"), "release");
+        assert_eq!(target_subdir_for("prod"), "prod");
+        assert_eq!(target_subdir_for("hot-loop"), "hot-loop");
+    }
+}