feat: add doctor command for diagnosing installs and cleaning stale daemon state (#1254)

* feat: add `doctor` command for install diagnostics and cleanup

Adds `agent-browser doctor`, a one-shot diagnostic that checks
environment, Chrome install, daemon state, config, encryption key,
providers, network reachability, and a live headless launch test.
Auto-cleans stale `.sock` / `.pid` / `.version` / `.stream` sidecar
files on every run. Destructive repairs (reinstall Chrome, purge old
state, close version-mismatched daemons, generate missing encryption
key) are gated behind `--fix`. Supports `--offline`, `--quick`, and
`--json`.

* fixes

cli/src/doctor/chrome.rs

@@ -0,0 +1,156 @@
+//! Check the Chrome install: binary path, version, cache dirs, user-data
+//! dir, and the optional lightpanda engine.
+
+use std::env;
+use std::path::{Path, PathBuf};
+
+use super::helpers::which_exists;
+use super::{Check, Status};
+
+pub(super) fn check(checks: &mut Vec<Check>) {
+    let category = "Chrome";
+
+    let chrome = crate::native::cdp::chrome::find_chrome();
+    match chrome {
+        Some(path) => {
+            let label = path.display().to_string();
+            match query_chrome_version(&path) {
+                Some(version) => checks.push(Check::new(
+                    "chrome.installed",
+                    category,
+                    Status::Pass,
+                    format!("{} at {}", version, label),
+                )),
+                None => checks.push(Check::new(
+                    "chrome.installed",
+                    category,
+                    Status::Pass,
+                    format!("Chrome at {} (version unknown)", label),
+                )),
+            }
+        }
+        None => checks.push(
+            Check::new(
+                "chrome.installed",
+                category,
+                Status::Fail,
+                "No Chrome binary found",
+            )
+            .with_fix("agent-browser install"),
+        ),
+    }
+
+    let cache_dir = crate::install::get_browsers_dir();
+    if cache_dir.exists() {
+        checks.push(Check::new(
+            "chrome.cache_dir",
+            category,
+            Status::Info,
+            format!("Cache dir {}", cache_dir.display()),
+        ));
+    }
+
+    if let Some(puppeteer_dir) = puppeteer_cache_dir() {
+        if puppeteer_dir.exists() {
+            checks.push(Check::new(
+                "chrome.puppeteer_cache",
+                category,
+                Status::Info,
+                format!(
+                    "Puppeteer cache also present: {} (will be used as a fallback)",
+                    puppeteer_dir.display()
+                ),
+            ));
+        }
+    }
+
+    if let Some(user_data_dir) = crate::native::cdp::chrome::find_chrome_user_data_dir() {
+        let profiles = crate::native::cdp::chrome::list_chrome_profiles(&user_data_dir);
+        let count = profiles.len();
+        let dir_label = user_data_dir.display().to_string();
+        if count == 0 {
+            checks.push(Check::new(
+                "chrome.user_data_dir",
+                category,
+                Status::Info,
+                format!(
+                    "Chrome user data dir found ({}), no profiles parsed",
+                    dir_label
+                ),
+            ));
+        } else {
+            checks.push(Check::new(
+                "chrome.user_data_dir",
+                category,
+                Status::Info,
+                format!("{} Chrome profile(s) at {}", count, dir_label),
+            ));
+        }
+    }
+
+    if let Ok(engine) = env::var("AGENT_BROWSER_ENGINE") {
+        if engine == "lightpanda" {
+            // Best-effort PATH lookup; absence is FAIL only when the user
+            // explicitly opted into the lightpanda engine.
+            if which_exists("lightpanda") {
+                checks.push(Check::new(
+                    "chrome.engine_lightpanda",
+                    category,
+                    Status::Pass,
+                    "Lightpanda binary on PATH",
+                ));
+            } else {
+                checks.push(
+                    Check::new(
+                        "chrome.engine_lightpanda",
+                        category,
+                        Status::Fail,
+                        "AGENT_BROWSER_ENGINE=lightpanda but no lightpanda binary on PATH",
+                    )
+                    .with_fix("install lightpanda or unset AGENT_BROWSER_ENGINE"),
+                );
+            }
+        }
+    }
+}
+
+fn query_chrome_version(path: &Path) -> Option<String> {
+    let output = std::process::Command::new(path)
+        .arg("--version")
+        .output()
+        .ok()?;
+    if !output.status.success() {
+        return None;
+    }
+    let s = String::from_utf8_lossy(&output.stdout).trim().to_string();
+    if s.is_empty() {
+        None
+    } else {
+        Some(s)
+    }
+}
+
+pub(super) fn puppeteer_cache_dir() -> Option<PathBuf> {
+    if let Ok(p) = env::var("PUPPETEER_CACHE_DIR") {
+        return Some(PathBuf::from(p));
+    }
+    dirs::home_dir().map(|h| h.join(".cache").join("puppeteer"))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_puppeteer_cache_dir_returns_sensible_default() {
+        // When PUPPETEER_CACHE_DIR is unset, we fall back to
+        // ~/.cache/puppeteer. Mutating env vars here would race with other
+        // tests, so just verify the fallback path is shaped correctly.
+        if env::var("PUPPETEER_CACHE_DIR").is_err() {
+            let dir = puppeteer_cache_dir().expect("home dir should resolve in tests");
+            let s = dir.to_string_lossy();
+            assert!(s.contains(".cache"));
+            assert!(s.ends_with("puppeteer"));
+        }
+    }
+}