Add Slice 4 tuner stack with AGENTS-compliant core types and HTTP API.

Introduces Si4684/ADAU1701 drivers, TunerService, FrequencyKHz,
SeekDirection, /api/tuner routes without file-scope globals, host tests,
and firmware blob tooling (binaries remain gitignored).

Co-authored-by: Cursor <cursoragent@cursor.com>

Software/components/net/include/net/NetBootstrap.hpp

@@ -27,6 +27,10 @@
 #include <expected>
 #include <optional>
 
+namespace tuner {
+class TunerService;
+} // namespace tuner
+
 namespace net {
 
 /**
@@ -47,6 +51,7 @@ public:
      *
      * @dname    start
      * @param    store  Secure store consulted for saved STA credentials.
+     * @param    tuner  Tuner service exposed by the HTTP API.
      * @return   NetBootstrap on success, or a NetError.
      * @pubstate none
      *
@@ -54,7 +59,7 @@ public:
      * @date     2026-07-06
      */
     [[nodiscard]] static std::expected<NetBootstrap, NetError>
-    start(core::ISecureStore& store);
+    start(core::ISecureStore& store, tuner::TunerService& tuner);
 
     NetBootstrap(const NetBootstrap&) = delete;
     NetBootstrap& operator=(const NetBootstrap&) = delete;

Software/components/net/include/net/SetupWebServer.hpp

@@ -23,10 +23,32 @@
 
 #include <expected>
 
+struct httpd_req;
+
+namespace tuner {
+class TunerService;
+} // namespace tuner
+
 struct httpd_handle;
 
 namespace net {
 
+/**
+ * @brief    HttpRouteContext — dependencies injected into HTTP handlers.
+ *
+ * @dname    HttpRouteContext
+ * @return   n/a (type)
+ * @pubstate Borrows store and tuner for the lifetime of SetupWebServer.
+ *           Passed as esp_http_server user_ctx (no file-scope globals).
+ *
+ * @author   Michele Bigi
+ * @date     2026-07-06
+ */
+struct HttpRouteContext {
+    core::ISecureStore* store;     ///< Secure store for Wi-Fi provisioning.
+    tuner::TunerService* tuner;    ///< Tuner service for tuner REST routes.
+};
+
 /**
  * @brief    SetupWebServer — setup UI, health, and Wi-Fi provisioning API.
  *
@@ -96,19 +118,23 @@ public:
      * @dname    start
      * @param    store     Secure store for POST /api/wifi persistence.
      * @param    netState  Active network phase exposed to handlers.
+     * @param    tuner     Tuner service for the tuner REST routes.
      * @return   Ok on success, or NetError::HttpServerStartFailed.
-     * @pubstate writes server_, store_, and netState_ on success.
+     * @pubstate writes server_, store_, netState_, and tuner_ on success.
      *
      * @author   Michele Bigi
      * @date     2026-07-06
      */
     [[nodiscard]] std::expected<void, NetError> start(core::ISecureStore& store,
-                                                      NetState netState);
+                                                      NetState netState,
+                                                      tuner::TunerService& tuner);
 
 private:
     httpd_handle* server_;
     core::ISecureStore* store_;
     NetState netState_;
+    tuner::TunerService* tuner_;
+    HttpRouteContext routeContext_;
 };
 
 } // namespace net