fix(installer): stop mislabeling stdout-style progress as stderr

Both installers (Electron bootstrap-runner + Tauri) hardcoded a literal
`stderr: ` prefix onto every line that arrived on fd 2. Tools like
uv/pip/git/npm write normal progress to stderr by design, so routine
install output showed up tagged as "stderr" (and rendered red in the
Tauri progress UI), making a healthy install look like it was erroring.

Carry the stream as structured metadata (`stream: 'stdout' | 'stderr'`)
on the log event instead of mangling the line text. The UI now styles
stderr subtly (dimmed) rather than alarmingly, and the persistent
forensic logs keep their stdout/stderr distinction.

apps/bootstrap-installer/src-tauri/src/bootstrap.rs

@@ -21,7 +21,7 @@ use serde::{Deserialize, Serialize};
 use tauri::{AppHandle, Emitter, State};
 use tokio::sync::{mpsc, Mutex};
 
-use crate::events::{BootstrapEvent, Manifest, StageState};
+use crate::events::{BootstrapEvent, LogStream, Manifest, StageState};
 use crate::install_script::{self, Pin, ScriptKind, ScriptSource};
 use crate::powershell::{self, StreamSink};
 use crate::AppState;
@@ -291,6 +291,7 @@ async fn run_bootstrap(
             BootstrapEvent::Log {
                 stage: None,
                 line: line.to_string(),
+                stream: LogStream::Stdout,
             },
         );
         // Bump to info-level so the line shows in bootstrap-installer.log
@@ -625,6 +626,7 @@ async fn run_install_script(
                 BootstrapEvent::Log {
                     stage: stage_for_stdout.clone(),
                     line: line.to_string(),
+                    stream: LogStream::Stdout,
                 },
             );
             // Tee to the rolling installer log so we have a persistent
@@ -643,7 +645,8 @@ async fn run_install_script(
                 &app_for_stderr,
                 BootstrapEvent::Log {
                     stage: stage_for_stderr.clone(),
-                    line: format!("stderr: {line}"),
+                    line: line.to_string(),
+                    stream: LogStream::Stderr,
                 },
             );
             // stderr-level lines get warn! so they're visually distinct

apps/bootstrap-installer/src-tauri/src/events.rs

@@ -51,6 +51,16 @@ pub enum StageState {
     Failed,
 }
 
+/// Which pipe a raw log line came from. Reported as structured metadata so
+/// the UI can style stderr subtly rather than mislabeling it as an error:
+/// uv/pip/git/npm write normal progress to stderr by design.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize)]
+#[serde(rename_all = "lowercase")]
+pub enum LogStream {
+    Stdout,
+    Stderr,
+}
+
 /// The single event channel `bootstrap` emits these. `type` discriminates.
 #[derive(Debug, Clone, Serialize)]
 #[serde(tag = "type", rename_all = "lowercase")]
@@ -72,11 +82,14 @@ pub enum BootstrapEvent {
         #[serde(skip_serializing_if = "Option::is_none")]
         error: Option<String>,
     },
-    /// Raw stdout/stderr line from install.ps1 (or our wrapper).
+    /// Raw stdout/stderr line from install.ps1 (or our wrapper). `stream`
+    /// tells the UI which pipe it came from so stderr can be styled subtly
+    /// instead of being mislabeled as an error.
     Log {
         #[serde(skip_serializing_if = "Option::is_none")]
         stage: Option<String>,
         line: String,
+        stream: LogStream,
     },
     /// Sent once when all stages complete successfully.
     Complete {

apps/bootstrap-installer/src-tauri/src/update.rs

@@ -28,7 +28,7 @@ use tauri::{AppHandle, Emitter};
 use tokio::io::{AsyncBufReadExt, BufReader};
 use tokio::process::Command;
 
-use crate::events::{BootstrapEvent, StageInfo, StageState};
+use crate::events::{BootstrapEvent, LogStream, StageInfo, StageState};
 
 /// `hermes update` exit code meaning "another hermes process is holding the
 /// venv shim open / dirty precondition" — see _cmd_update_impl in
@@ -237,6 +237,7 @@ async fn run_update(app: AppHandle) -> Result<()> {
         emit_log(
             &app,
             None,
+            LogStream::Stdout,
             &format!("[update] could not auto-launch desktop: {err}. Launch Hermes manually."),
         );
     }
@@ -251,7 +252,7 @@ async fn wait_for_venv_free(install_root: &Path, app: &AppHandle) {
     let shim = venv_hermes(install_root);
     let deadline = Instant::now() + DESKTOP_EXIT_WAIT;
 
-    emit_log(app, Some("update"), "[update] waiting for Hermes to exit…");
+    emit_log(app, Some("update"), LogStream::Stdout, "[update] waiting for Hermes to exit…");
 
     loop {
         if !is_locked(&shim) {
@@ -261,6 +262,7 @@ async fn wait_for_venv_free(install_root: &Path, app: &AppHandle) {
             emit_log(
                 app,
                 Some("update"),
+                LogStream::Stdout,
                 "[update] timed out waiting for Hermes to exit; proceeding anyway",
             );
             return;
@@ -320,22 +322,22 @@ async fn run_streamed(
     loop {
         tokio::select! {
             line = out.next_line() => match line {
-                Ok(Some(l)) => emit_log(app, stage_owned.as_deref(), &l),
+                Ok(Some(l)) => emit_log(app, stage_owned.as_deref(), LogStream::Stdout, &l),
                 Ok(None) => break,
                 Err(e) => { tracing::warn!("stdout read error: {e}"); break; }
             },
             line = err.next_line() => match line {
-                Ok(Some(l)) => emit_log(app, stage_owned.as_deref(), &format!("stderr: {l}")),
+                Ok(Some(l)) => emit_log(app, stage_owned.as_deref(), LogStream::Stderr, &l),
                 Ok(None) => {}
                 Err(e) => { tracing::warn!("stderr read error: {e}"); }
             },
         }
     }
     while let Ok(Some(l)) = out.next_line().await {
-        emit_log(app, stage_owned.as_deref(), &l);
+        emit_log(app, stage_owned.as_deref(), LogStream::Stdout, &l);
     }
     while let Ok(Some(l)) = err.next_line().await {
-        emit_log(app, stage_owned.as_deref(), &format!("stderr: {l}"));
+        emit_log(app, stage_owned.as_deref(), LogStream::Stderr, &l);
     }
 
     let status = child.wait().await.map_err(|e| anyhow!("waiting for child: {e}"))?;
@@ -429,7 +431,7 @@ fn emit_stage(
     );
 }
 
-fn emit_log(app: &AppHandle, stage: Option<&str>, line: &str) {
+fn emit_log(app: &AppHandle, stage: Option<&str>, stream: LogStream, line: &str) {
     match stage {
         Some(s) => tracing::info!(target: "bootstrap.log", stage = %s, "{line}"),
         None => tracing::info!(target: "bootstrap.log", "{line}"),
@@ -439,6 +441,7 @@ fn emit_log(app: &AppHandle, stage: Option<&str>, line: &str) {
         BootstrapEvent::Log {
             stage: stage.map(|s| s.to_string()),
             line: line.to_string(),
+            stream,
         },
     );
 }