feat: initial OpenFUT Launcher

GUI desktop app (egui/eframe) that manages the openfut-core and
openfut-bridge services with a single window.

- Dashboard: start/stop each service independently or together; live
  status indicators; quick-status for cert and hosts
- Logs: real-time stdout/stderr from both processes, colour-coded by
  level, follow mode and manual clear
- Setup: add/remove EA hostname redirects in /etc/hosts (pkexec/sudo);
  install the bridge TLS cert into the system CA store
- Config: all binary paths and env vars editable in-app; persisted to
  ~/.config/openfut-launcher/config.json

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/logs.rs

@@ -0,0 +1,34 @@
+use std::collections::VecDeque;
+
+const MAX_LINES: usize = 2000;
+
+pub struct LogBuffer {
+    lines: VecDeque<String>,
+    pub dirty: bool,
+}
+
+impl LogBuffer {
+    pub fn new() -> Self {
+        Self {
+            lines: VecDeque::with_capacity(MAX_LINES),
+            dirty: false,
+        }
+    }
+
+    pub fn push(&mut self, line: String) {
+        if self.lines.len() >= MAX_LINES {
+            self.lines.pop_front();
+        }
+        self.lines.push_back(line);
+        self.dirty = true;
+    }
+
+    pub fn lines(&self) -> impl Iterator<Item = &str> {
+        self.lines.iter().map(String::as_str)
+    }
+
+    pub fn clear(&mut self) {
+        self.lines.clear();
+        self.dirty = true;
+    }
+}