feat: a herdr pane says which Claude account its agent is running as

CHANGELOG.md

@@ -81,6 +81,28 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   through. A verb that forwards no login says it is ignoring it, as `--devcontainer`
   does; a global command refuses it.
 
+- **A pane's row in [herdr](https://herdr.dev) says which account the agent in it is
+  running as**, reported as the display label `profile=<name>`. A profile is chosen per
+  launch and forwarded per session, so two tabs side by side can be two different
+  accounts with nothing on screen to tell them apart, and the failure that matters here
+  is not noticing: work pushed from the wrong identity is found out about later and
+  somewhere else. Reported under devlaunch's own source name, so it sits beside herdr's
+  labels rather than overwriting one, and cleared rather than left stale when a launch
+  forwards the default login.
+
+  **A pane opened beside an agent inherits the profile that agent started with.** The
+  pane shell already opens in the workspace its tab holds; a workspace is not an account,
+  so it read the default login while the agent one pane over ran as another. It is read
+  from the agent's own argv rather than from a note kept anywhere, for the reason the
+  pane shell keeps nothing: the argv is what is true, and a record would be a second copy
+  of it that can go stale. An exact element match, and it stops at a bare `--`, so a
+  prompt that contains the words `--claude-profile work` is a prompt.
+
+  **Nothing is inherited across a boundary.** A pane in a tab holding no agent has no
+  account to inherit and gets the default login, and the environment of an agent already
+  running is fixed at exec, so switching profile reaches the next session and never the
+  one on screen.
+
 ### Fixed
 
 - **`$CLAUDE_CONFIG_DIR` is now honoured on the host, so a host that has moved its

rust/devlaunch-core/public-api.rest.txt

@@ -2756,7 +2756,9 @@ impl core::marker::StructuralPartialEq for devlaunch_core::flows::repo_manager::
 pub mod devlaunch_core::flows::session_manager
 pub enum devlaunch_core::flows::session_manager::PaneDestination
 pub devlaunch_core::flows::session_manager::PaneDestination::HostShell
-pub devlaunch_core::flows::session_manager::PaneDestination::Workspace(alloc::string::String)
+pub devlaunch_core::flows::session_manager::PaneDestination::Workspace
+pub devlaunch_core::flows::session_manager::PaneDestination::Workspace::claude_profile: core::option::Option<alloc::string::String>
+pub devlaunch_core::flows::session_manager::PaneDestination::Workspace::workspace_id: alloc::string::String
 impl core::clone::Clone for devlaunch_core::flows::session_manager::PaneDestination
 pub fn devlaunch_core::flows::session_manager::PaneDestination::clone(&self) -> devlaunch_core::flows::session_manager::PaneDestination
 impl core::cmp::Eq for devlaunch_core::flows::session_manager::PaneDestination

rust/devlaunch-core/src/clients/herdr.rs

@@ -1234,6 +1234,53 @@ pub(crate) fn pane_list_argv() -> Vec<String> {
     vec!["pane".to_owned(), "list".to_owned()]
 }
 
+/// The source id devlaunch reports under, in herdr's `--source` sense.
+///
+/// One string, two callers: this module's argv builders and [`HOOK`], which spells it
+/// as a shell literal because it is a shell script.
+/// `the_hook_reports_under_the_source_this_module_names` is the test that diffs them.
+pub(crate) const REPORT_SOURCE: &str = "devlaunch:claude";
+
+/// The metadata token naming the Claude profile a pane's session forwards.
+///
+/// Display-only, and rendered as `$profile` in herdr's agent sidebar rows. A *token*
+/// rather than `--display-agent`, which would fight the agent name `report-agent`
+/// sets and which herdr uses to pick a detection manifest.
+pub(crate) const PROFILE_TOKEN: &str = "profile";
+
+/// The argv that labels a pane with the Claude profile its session runs as, or clears
+/// the label when the session names no profile.
+///
+/// **Clearing matters as much as setting.** A pane is reused: a launch that named
+/// `work` and a later launch in the same pane that named nothing would otherwise leave
+/// the sidebar claiming an account the running session is not using, which is the exact
+/// mislabelling `--claude-profiles` exists to prevent, moved somewhere more visible.
+///
+/// Verified against herdr 0.8.2: `pane report-metadata [OPTIONS] --source <ID>
+/// <PANE_ID>`, with `--token NAME=VALUE` and `--clear-token NAME`. The pane id is given
+/// first, as [`HOOK`] gives it to `report-agent`, which is the invocation measured
+/// against a live herdr.
+pub(crate) fn profile_metadata_argv(pane_id: &str, profile: Option<&str>) -> Vec<String> {
+    let mut args = vec![
+        "pane".to_owned(),
+        "report-metadata".to_owned(),
+        pane_id.to_owned(),
+        "--source".to_owned(),
+        REPORT_SOURCE.to_owned(),
+    ];
+    match profile {
+        Some(name) => {
+            args.push("--token".to_owned());
+            args.push(format!("{PROFILE_TOKEN}={name}"));
+        }
+        None => {
+            args.push("--clear-token".to_owned());
+            args.push(PROFILE_TOKEN.to_owned());
+        }
+    }
+    args
+}
+
 /// The argv that asks herdr what one pane is running.
 pub(crate) fn process_info_argv(pane_id: &str) -> Vec<String> {
     vec![

rust/devlaunch-core/src/flows/launch.rs

@@ -2205,6 +2205,15 @@
                 pane_id: reporting.pane_id().to_owned(),
                 socket: reporting.container_socket(),
             });
+            // Which account this session runs as, so the manager's sidebar says so
+            // rather than leaving the name of a directory as the only clue. Called
+            // even when no profile was named, because a pane is reused and a stale
+            // label is worse than none.
+            session_manager::report_profile(
+                session.runner,
+                &reporting,
+                session.host.claude.profile.as_deref(),
+            );
             Some((reporting, forward))
         }
         session_manager::Prepared::Refused { reason } => {