M7: touch + outbound /state POST to Scrypted

state_client.{h,c}:
- Worker task drains a depth-1 queue (xQueueOverwrite gives the
  replace-on-full semantics from the spec — in-flight POST is never
  cancelled; the next queued entry is overwritten by newer state).
- esp_http_client POST to <scrypted>/state with Content-Type application/
  json, User-Agent ScryptedViewport/<version>, Connection: close, 1s
  timeout. Body: {"viewport":"<name>","state":"wake"|"sleep"}.
- Any non-2xx or transport error increments state_post_failures and is
  otherwise ignored. Silently drops if no Scrypted URL is configured.

touch.{h,c}:
- FT5426 capacitive touch on the shared I2C bus at 0x38.
- 30ms polling task; tracks down/up transitions, detects taps as
  down-then-up within 500ms with a 150ms debounce.
- On tap, toggles wake/sleep via state_machine_set_local(), which drives
  the local transition AND fires state_client_post() at Scrypted.

state_machine adds state_machine_set_local(): runs the same transition
as state_machine_set() then enqueues an outbound POST. Idle-timer
expiry now uses this path so Scrypted sees idle-driven sleeps too
(the spec's "tighten the race with /frame 409" path stays in place as
the fallback).

display.h exposes display_i2c_bus(); touch.c uses it instead of
re-initializing the same I2C port.

app_main starts state_client right after the state machine and starts
touch after display init (touch is skipped if display isn't up since
they share the bus).

CMakeLists.txt: add esp_http_client to REQUIRES.

Build clean against ESP-IDF 5.4 (binary ~860 KB; jumped ~210 KB from
M6 because esp_http_client + cJSON path pulls in tcp_transport, mbedtls,
http_parser).

TESTING.md M7: flask-based test receiver, tap dispatch verification,
failure-path check (kill receiver, confirm counter increments),
queue-coalescing behavior, no-POST-on-Scrypted-initiated, no-POST-
when-unconfigured.

1 files changed, 12 insertions, 2 deletions

diff --git a/main/state_machine.c b/main/state_machine.c
index 22f3f56..2808738 100644
--- a/main/state_machine.c
+++ b/main/state_machine.c
@@ -5,6 +5,7 @@
 #include "esp_timer.h"
 
 #include "display.h"
+#include "state_client.h"
 
 static const char *TAG = "state";
 
@@ -28,8 +29,7 @@ static void disarm_idle_timer(void)
 static void idle_timer_fired(void *arg)
 {
     ESP_LOGI(TAG, "idle timer expired — sleeping");
-    state_machine_set(VIEWPORT_STATE_ASLEEP);
-    // TODO M7: state_client_post(VIEWPORT_STATE_ASLEEP);  // tell Scrypted
+    state_machine_set_local(VIEWPORT_STATE_ASLEEP);
 }
 
 esp_err_t state_machine_init(void)
@@ -80,6 +80,16 @@ void state_machine_frame_painted(void)
     if (awake) arm_idle_timer_unlocked();
 }
 
+void state_machine_set_local(viewport_run_state_t target)
+{
+    // For idempotent no-op (already in target), state_machine_set returns OK
+    // without changing state; we still call state_client to keep Scrypted in
+    // sync if it's drifted. State POSTs are idempotent on both ends.
+    esp_err_t err = state_machine_set(target);
+    if (err != ESP_OK) return;  // unconfigured / invalid
+    state_client_post(target);
+}
+
 viewport_run_state_t state_machine_current(void)
 {
     viewport_state_lock();