chore: auto-commit (13 archivos)

- CMakeLists.txt
- agent_protocol.cpp
- agent_protocol.h
- app.md
- appicon.ico
- hosts_db.cpp
- hosts_db.h
- http_client.cpp
- http_client.h
- main.cpp
- ...

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

hosts_db.h

@@ -0,0 +1,38 @@
+#pragma once
+#include <string>
+#include <vector>
+#include <cstdint>
+
+struct sqlite3;
+
+namespace pex {
+
+struct Host {
+    int64_t id = 0;
+    std::string name;
+    std::string url;
+    std::string token;
+    std::string os;            // "linux" | "windows" | "wsl"
+    int64_t last_seen_unix = 0;
+    bool is_local = false;
+};
+
+class HostsDb {
+public:
+    HostsDb();
+    ~HostsDb();
+
+    // path debe ser absoluto (fn::local_path("hosts.db")).
+    bool open(const std::string& path);
+    void close();
+
+    std::vector<Host> list();
+    int64_t upsert(const Host& h);   // devuelve id; -1 si falla
+    bool remove(int64_t id);
+    bool touch_last_seen(int64_t id, int64_t unix_ts);
+
+private:
+    sqlite3* db_ = nullptr;
+};
+
+} // namespace pex