feat(install): auto-start the dashboard on boot via systemd, no Claude Code needed

Adds ccam service install/uninstall/status for checkout installs and wires
the same systemd --user unit into plugin-bootstrap.js, so plugin-installed
colleagues get boot persistence too instead of needing a Claude Code
session to (re)start the server after every reboot.

scripts/plugin-bootstrap.js

@@ -8,7 +8,10 @@
  *
  * The worker installs runtime dependencies, removes hook entries left behind by
  * an older `npm run install-hooks` (they would double-count every event), puts
- * the `ccam` CLI on PATH, and starts the dashboard server detached.
+ * the `ccam` CLI on PATH, and starts the dashboard server — as a systemd
+ * `--user` service when available (see `systemd-service.js`), so it survives
+ * reboots without Claude Code being opened first; otherwise a detached spawn
+ * scoped to this session, same as before.
  *
  * Everything writable lives under `~/.claude/agent-dashboard/runtime/` — NOT in
  * the plugin cache, which Claude Code garbage-collects and replaces wholesale
@@ -466,8 +469,38 @@ function bootstrap(rt = runtimeDir(), { force = false } = {}) {
     }
 
     if (movedRoot || !serverIsLive()) {
-      const pid = startDashboard(rt);
-      log(rt, `started the dashboard server (pid ${pid})`);
+      const svc = require("./systemd-service");
+      const result = svc.systemctlAvailable()
+        ? svc.installUserService({
+            name: "ccam",
+            description: "CCAM dashboard server (Claude Code plugin)",
+            workingDir: PLUGIN_ROOT,
+            execStart: `${process.execPath} ${path.join(PLUGIN_ROOT, "server", "index.js")}`,
+            env: {
+              NODE_ENV: "production",
+              NODE_PATH: path.join(rt, "node_modules"),
+              DASHBOARD_CLIENT_DIST: path.join(rt, "client-dist"),
+            },
+          })
+        : "unavailable";
+      if (result === "written" || result === "unchanged") {
+        if (result === "written") svc.enableLinger();
+        log(
+          rt,
+          result === "written"
+            ? "installed a systemd --user service — the dashboard now survives reboots without Claude Code"
+            : "systemd --user service already up to date"
+        );
+      } else {
+        // No systemd (macOS/Windows/WSL without it), or the unit exists but
+        // wasn't ours to touch — same detached-spawn fallback as before,
+        // scoped to this session only.
+        const pid = startDashboard(rt);
+        log(
+          rt,
+          `started the dashboard server (pid ${pid})${result === "foreign" ? " — a foreign systemd unit named 'ccam' already exists" : ""}`
+        );
+      }
     }
 
     writeState(