Add bounded dictation state and persistent offline Redux worker

src/worker.hpp

@@ -0,0 +1,37 @@
+#pragma once
+
+#include <cstdint>
+#include <chrono>
+#include <memory>
+#include <optional>
+#include <string>
+#include <vector>
+
+namespace frameyap {
+
+struct WorkerReply {
+    uint64_t id;
+    std::string text;
+    std::string error;
+};
+
+class Worker {
+public:
+    explicit Worker(std::chrono::milliseconds warmup_timeout = std::chrono::seconds(120),
+                    std::chrono::milliseconds request_timeout = std::chrono::seconds(60));
+    ~Worker();
+    Worker(const Worker&) = delete;
+    Worker& operator=(const Worker&) = delete;
+    void start(const std::string& python, const std::string& script,
+               const std::string& model, int threads = 2);
+    bool ready() const;
+    void submit(uint64_t id, const std::vector<float>& pcm);
+    std::optional<WorkerReply> poll();
+    void stop();
+
+private:
+    struct State;
+    std::unique_ptr<State> state_;
+};
+
+} // namespace frameyap