Updates from Gitea, step 2: the connection (check and list work on the device)

The roots (ISRG X1 and X2), an HTTPS client that reads the answer as a
stream, GiteaReleases (the latest and a list of ten), the Update
Service's requests, install from Gitea through the existing install path,
the daily check's schedule, the Check for updates setting, and console
commands: update check | list | status | install <tag>.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EhqxQ49eCju4CzKYNjZzwT

src/services/gitea_releases.h

@@ -0,0 +1,47 @@
+#pragma once
+
+#include <freertos/FreeRTOS.h>
+#include <freertos/semphr.h>
+
+#include <string>
+#include <vector>
+
+#include "release_info.h"
+
+namespace roro {
+
+// What the device knows of the project's releases on Gitea (docs/milestones/R1.md, #6): the latest,
+// and a list of the last ten. The fetching runs on the Update Service's task; the screens read what
+// came out, from the main loop.
+class GiteaReleases {
+   public:
+    enum class Status : uint8_t { Never, Busy, Done, Failed };
+    static constexpr size_t kListSize = 10;
+
+    GiteaReleases() : lock_(xSemaphoreCreateMutex()) {}
+
+    // On the Update Service's task. True when the answer was read; otherwise error() says why.
+    bool fetchLatest();
+    bool fetchList();
+
+    Status status() const;
+    std::string error() const;
+    uint32_t seq() const;  // grows with every answer that changed something
+    bool latest(release::Release& out) const;          // false: not fetched yet
+    std::vector<release::Release> list() const;
+    bool find(const std::string& tag, release::Release& out) const;  // in the list, or the latest
+
+   private:
+    bool fetch(const std::string& path, size_t max, std::vector<release::Release>& out);
+    void finish(bool ok, const std::string& error);
+
+    mutable SemaphoreHandle_t lock_;
+    Status status_ = Status::Never;
+    std::string error_;
+    uint32_t seq_ = 0;
+    bool haveLatest_ = false;
+    release::Release latest_;
+    std::vector<release::Release> list_;
+};
+
+}  // namespace roro