Phase 5: Wi-Fi manager w/ reconnect, Scryfall HTTPS client + cJSON caching to /spiffs on net_task (Core 0)

main/scryfall_client.h

@@ -0,0 +1,56 @@
+/*
+ * MTG RFID Companion - Scryfall API client (Core 0)
+ *
+ * Phase 5: HTTPS card lookups with cJSON parsing and LittleFS caching of
+ * metadata + card art. Runs on the dedicated net_task.
+ */
+
+#pragma once
+
+#include "esp_err.h"
+#include <stdbool.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define SCRYFALL_API      "https://api.scryfall.com"
+#define SCRYFALL_CARD_ARTS_URL "/cards/named?exact="
+
+/**
+ * @brief Start the net_task (waits for Wi-Fi, prefetches mapping cache,
+ *        then serves fetch requests). Must be called after wifi start.
+ */
+esp_err_t scryfall_client_start(void);
+
+/**
+ * @brief Queue an async fetch by exact card name (net_task performs it).
+ * @param card_name Exact card name, e.g. "Sol Ring"
+ * @param uid Uppercase hex UID used for cache filenames
+ */
+esp_err_t scryfall_fetch_request(const char *card_name, const char *uid);
+
+/**
+ * @brief Synchronously ensure the card cache exists for uid; fetch if missing.
+ *        Safe to call from net_task only.
+ */
+esp_err_t scryfall_ensure_cached(const char *card_name, const char *uid);
+
+/**
+ * @brief True if net_task finished caching a card since last consumption.
+ */
+bool scryfall_has_pending_result(void);
+
+/**
+ * @brief UID of the most recently cached card.
+ */
+const char *scryfall_last_result_uid(void);
+
+/**
+ * @brief Clear the pending-result flag.
+ */
+void scryfall_consume_result(void);
+
+#ifdef __cplusplus
+}
+#endif