fix(browser): platform-aware error messages with WSL detection

- Add is_wsl() detection via /proc/version
- Add example_npx_path() returning platform-appropriate example path
- Replace all hardcoded macOS paths in error messages with dynamic ones
- Add WSL-specific hints: Node.js must be installed inside WSL, not Windows
- WSL hint includes nvm install instructions
- Clean build: 0 errors, 0 warnings

crates/gyandoot-agent/src/browser_manager.rs

@@ -11,12 +11,19 @@
 //! 3. Waits for the Unix socket to appear (up to 30 seconds)
 //! 4. Returns a ready-to-use `BrowserClient`
 //!
-//! # Cross-platform npx resolution
+//! Cross-platform npx resolution
 //!
 //! The daemon is started via Node.js's `npx`. Resolution order:
 //! 1. `config.browser.node_path` — explicit path in config (e.g.
 //!    `/home/user/.nvm/versions/node/v22/bin/npx`)
 //! 2. `"npx"` on Linux/macOS, `"npx.cmd"` on Windows — PATH lookup
+//!
+//! WSL Detection
+//!
+//! Windows Subsystem for Linux is detected by reading `/proc/version` for
+//! the presence of "microsoft" or "wsl" (case-insensitive). WSL-specific
+//! error messages guide users to ensure Node.js is installed via nvm or
+//! fnm inside WSL (not via the Windows-side Node).
 
 use std::time::Duration;
 
@@ -61,6 +68,28 @@ fn resolve_npx(node_path: Option<&str>) -> &str {
     }
 }
 
+/// Detect if we're running inside Windows Subsystem for Linux (WSL).
+///
+/// Checks `/proc/version` for the presence of "microsoft" or "wsl"
+/// (case-insensitive). Returns `true` if WSL is detected.
+fn is_wsl() -> bool {
+    std::fs::read_to_string("/proc/version")
+        .map(|content| {
+            let lower = content.to_lowercase();
+            lower.contains("microsoft") || lower.contains("wsl")
+        })
+        .unwrap_or(false)
+}
+
+/// Get a platform-aware example npx path for error messages.
+fn example_npx_path() -> &'static str {
+    if cfg!(target_os = "macos") {
+        "\"/Users/yourname/.nvm/versions/node/v22/bin/npx\""
+    } else {
+        "\"/home/user/.nvm/versions/node/v22/bin/npx\""
+    }
+}
+
 /// Initialize the camoufox-browser daemon and return a ready client.
 ///
 /// `node_path` — optional explicit path to `npx`/`npx.cmd` (from
@@ -93,7 +122,7 @@ pub async fn init_browser(node_path: Option<&str>) -> BrowserInitResult {
                 }
                 Ok(false) => {
                     let msg = format!(
-                        "Daemon did not start within {}s — socket not found at {}",
+                        "Daemon did not start within {}s \u{2014} socket not found at {}",
                         DAEMON_STARTUP_TIMEOUT_SECS,
                         socket_path.display()
                     );
@@ -109,18 +138,33 @@ pub async fn init_browser(node_path: Option<&str>) -> BrowserInitResult {
         }
         Err(e) => {
             let npx_name = resolve_npx(node_path);
-            let msg = format!(
+            let mut msg = format!(
                 "Could not start camoufox daemon: {}\n\n\
                  Make sure Node.js v20+ and the package are installed:\n  \
                  npm install -g camoufox-browser\n  \
                  {} camoufox-browser@latest install\n\n\
                  If Node is installed via nvm/fnm/asdf, set browser.node_path\n\
-                 in your config, e.g.:\n  \
+                 in your config:\n  \
                  [browser]\n  \
-                 node_path = \"/home/user/.nvm/versions/node/v22/bin/npx\"\n\n\
+                 node_path = {}\n\n\
                  Then try again.",
-                e, npx_name
+                e, npx_name, example_npx_path()
             );
+
+            // Add WSL-specific hints
+            if is_wsl() {
+                msg.push_str(
+                    "\n\n\u{26a0}\u{fe0f}  WSL detected: Make sure Node.js is installed INSIDE WSL\n\
+                     (e.g., via nvm or fnm in your WSL terminal). The Windows-side\n\
+                     Node.js is not accessible from WSL by default.\n\
+                     Test with: which npx\n\
+                     If 'which npx' returns empty, run:\n  \
+                     curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.1/install.sh | bash\n  \
+                     nvm install 22\n\
+                     Then run 'gyandoot run' again.",
+                );
+            }
+
             warn!("{}", msg);
             BrowserInitResult::Unavailable(msg)
         }
@@ -148,11 +192,27 @@ async fn trigger_daemon_start(session: &str, node_path: Option<&str>) -> Result<
         .await
         .map_err(|e| {
             let hint = if node_path.is_none() {
-                "\n  → Set [browser].node_path in your config, e.g.:\n    [browser]\n    node_path = \"/Users/yourname/.nvm/versions/node/v22/bin/npx\"".to_string()
+                format!(
+                    "\n  \u{2192} Set [browser].node_path in your config:\n    [browser]\n    node_path = {}",
+                    example_npx_path()
+                )
             } else {
-                format!("\n  → npx at '{}' not found or not executable", npx)
+                format!("\n  \u{2192} npx at '{}' not found or not executable", npx)
             };
-            format!("{} failed: {}. Is Node.js installed?{}", npx, e, hint)
+
+            let wsl_hint = if is_wsl() {
+                "\n\n\u{26a0}\u{fe0f}  WSL detected: npx was not found. Install Node.js inside WSL:\n  \
+                 curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.1/install.sh | bash\n  \
+                 nvm install 22"
+                    .to_string()
+            } else {
+                String::new()
+            };
+
+            format!(
+                "{} failed: {}. Is Node.js installed?{}{}",
+                npx, e, hint, wsl_hint
+            )
         })?;
 
     if !output.status.success() {
@@ -169,17 +229,27 @@ async fn trigger_daemon_start(session: &str, node_path: Option<&str>) -> Result<
         ));
 
         let hint = if node_path.is_none() {
-            "\n  → Try setting [browser].node_path in your config:\n    [browser]\n    node_path = \"/Users/yourname/.nvm/versions/node/v22/bin/npx\"".to_string()
+            format!(
+                "\n  \u{2192} Try setting [browser].node_path in your config:\n    [browser]\n    node_path = {}",
+                example_npx_path()
+            )
+        } else {
+            String::new()
+        };
+
+        let wsl_hint = if is_wsl() {
+            "".to_string()
         } else {
             String::new()
         };
 
         return Err(format!(
-            "camoufox-browser failed (exit: {}):\n  {}\n  → Full log saved to {}{}",
+            "camoufox-browser failed (exit: {}):\n  {}\n  \u{2192} Full log saved to {}{}{}",
             output.status.code().unwrap_or(-1),
             details,
             log_file.display(),
             hint,
+            wsl_hint,
         ));
     }