Tidy: delete dead code, inline single-use helpers, fix double-lock

Code-review pass after the M5 colour fix. -126 net lines (-215 / +89).

Dead code removed:
- display_fill, display_test_pattern — M3 bring-up self-tests, no callers
- net_eth_is_up — no callers
- nvs_config_reset — no callers (factory-reset gesture was removed earlier;
  NVS wipe now goes through `idf.py erase-flash`)

Helpers inlined or collapsed (each had one call site):
- state_name / orientation_name — ternaries at the cJSON site
- fmt_bytes / fmt_uptime — inline scope in local_screens_show_info
- expected_dims (http_api) + effective_dims (local_screens) — merged into
  viewport_state_effective_dims() in viewport_state, one canonical source

state_machine cleanup:
- arm_idle_timer_unlocked / disarm_idle_timer collapsed to one arm_idle_timer(ms)
  that takes the snapshotted timeout (ms==0 disables). Removes the misleading
  name and the second viewport_state lock acquisition per painted frame.
- state_machine_set + state_machine_frame_painted now snapshot state + idle_ms
  under one lock.

mdns_service cleanup:
- snapshot_state / apply_hostname / apply_txt collapsed into a single
  apply_state(include_hostname) helper; mdns_service_start grabs hostname
  once for hostname_set + log instead of going under the lock three times.

http_api cleanup:
- POST /config brightness-changed path uses the local `bright` it already
  validated instead of re-locking + re-reading st->brightness.
- Trimmed verbose bring-up comments (stack-size justification, M5 saga,
  DSI shadow struct) to one line each — kept the load-bearing facts.

Smoke-tested on hardware: boot clean, display + JPEG + touch all up
([DJT]), info screen renders, no crashes.

12 files changed, 89 insertions, 215 deletions

diff --git a/main/display.c b/main/display.c
index 13babdb..a704891 100644
--- a/main/display.c
+++ b/main/display.c
@@ -101,13 +101,8 @@ enum {
 #define TC_PPI_STARTPPI           0x0104
 #define TC_DSI_STARTDSI           0x0204
 
-// Shadow of esp_lcd_dsi_bus_t. The IDF private struct is
-//   { int bus_id; mipi_dsi_hal_context_t hal; esp_pm_lock_handle_t pm_lock; }
-// (esp-idf/components/esp_lcd/dsi/mipi_dsi_priv.h). We only need bus_id +
-// hal to reach the LL/HAL APIs, so the trailing pm_lock is fine to ignore.
-// If the IDF layout shifts in a future release this is the place that
-// breaks first — guarded by ESP-IDF version is overkill until it actually
-// breaks.
+// Mirror of esp_lcd_dsi_bus_t (esp-idf/components/esp_lcd/dsi/mipi_dsi_priv.h)
+// — needed to reach the HAL/LL APIs for the TC358762 bridge init.
 typedef struct {
     int                    bus_id;
     mipi_dsi_hal_context_t hal;
@@ -424,12 +419,9 @@ esp_err_t display_wake(void)
     return err;
 }
 
-// RGB565 → RGB888 in B,G,R byte order. The ESP32-P4 DSI engine + TC358762
-// bridge pipeline expects BGR on the wire for the panel's RGB channels —
-// writing R first paints pure blue as solid red on the panel (verified
-// with the M5 self-test: decoded buffer holds 0x001F, panel showed red).
-// Symmetric pixels (white text on black) don't expose this; saturated
-// channel inputs do.
+// RGB565 → 24-bit pixel in B,G,R memory order — what the DSI engine +
+// TC358762 + Pi panel pipeline expects (the "RGB888" label refers to the
+// MIPI wire bit order, not byte position in PSRAM).
 static inline void rgb565_to_rgb888(uint16_t px, uint8_t *out)
 {
     out[0] = (uint8_t)(( px        & 0x1F) * 255 / 31);  // B
@@ -437,22 +429,6 @@ static inline void rgb565_to_rgb888(uint16_t px, uint8_t *out)
     out[2] = (uint8_t)(((px >> 11) & 0x1F) * 255 / 31);  // R
 }
 
-esp_err_t display_fill(uint16_t rgb565)
-{
-    if (!s_up || !s_rot_buf) return ESP_ERR_INVALID_STATE;
-    uint8_t rgb[3];
-    rgb565_to_rgb888(rgb565, rgb);
-    size_t n = PANEL_H_ACTIVE * PANEL_V_ACTIVE;
-    for (size_t i = 0; i < n; ++i) {
-        s_rot_buf[i * 3 + 0] = rgb[0];
-        s_rot_buf[i * 3 + 1] = rgb[1];
-        s_rot_buf[i * 3 + 2] = rgb[2];
-    }
-    return esp_lcd_panel_draw_bitmap(s_panel, 0, 0,
-                                     PANEL_H_ACTIVE, PANEL_V_ACTIVE,
-                                     s_rot_buf);
-}
-
 esp_err_t display_present_rgb565(const uint16_t *src,
                                  uint16_t        src_w,
                                  uint16_t        src_h)
@@ -463,8 +439,6 @@ esp_err_t display_present_rgb565(const uint16_t *src,
     viewport_orientation_t orient = viewport_state_get()->orientation;
     viewport_state_unlock();
 
-    if (!s_rot_buf) return ESP_ERR_INVALID_STATE;
-
     if (orient == VIEWPORT_ORIENTATION_LANDSCAPE) {
         if (src_w != PANEL_H_ACTIVE || src_h != PANEL_V_ACTIVE)
             return ESP_ERR_INVALID_SIZE;
@@ -489,24 +463,3 @@ esp_err_t display_present_rgb565(const uint16_t *src,
                                      PANEL_H_ACTIVE, PANEL_V_ACTIVE,
                                      s_rot_buf);
 }
-
-esp_err_t display_test_pattern(void)
-{
-    if (!s_up || !s_rot_buf) return ESP_ERR_INVALID_STATE;
-    static const uint16_t bars[8] = {
-        0xFFFF, 0xFFE0, 0x07FF, 0x07E0,
-        0xF81F, 0xF800, 0x001F, 0x0000,
-    };
-    const int bar_w = PANEL_H_ACTIVE / 8;
-    for (int y = 0; y < PANEL_V_ACTIVE; ++y) {
-        for (int x = 0; x < PANEL_H_ACTIVE; ++x) {
-            int b = x / bar_w;
-            if (b > 7) b = 7;
-            size_t idx = ((size_t)y * PANEL_H_ACTIVE + x) * 3;
-            rgb565_to_rgb888(bars[b], &s_rot_buf[idx]);
-        }
-    }
-    return esp_lcd_panel_draw_bitmap(s_panel, 0, 0,
-                                     PANEL_H_ACTIVE, PANEL_V_ACTIVE,
-                                     s_rot_buf);
-}
diff --git a/main/display.h b/main/display.h
index 3119a60..9092efb 100644
--- a/main/display.h
+++ b/main/display.h
@@ -27,14 +27,6 @@ esp_err_t display_set_brightness(uint8_t brightness_0_100);
 esp_err_t display_sleep(void);
 esp_err_t display_wake(void);
 
-// Paint a solid RGB565 color to the entire framebuffer + flush.
-// Used by M3 for the test pattern and by local_screens for the IP and
-// loading screens (M8).
-esp_err_t display_fill(uint16_t rgb565);
-
-// Show a deterministic test pattern (vertical color bars). M3 acceptance.
-esp_err_t display_test_pattern(void);
-
 // Blit an RGB565 source image to the panel, applying the current
 // orientation. Source dimensions must match the effective resolution:
 //   portrait  -> src is 480x800 (rotated 90° CW into the 800x480 panel)
diff --git a/main/http_api.c b/main/http_api.c
index dce57bb..028d3a7 100644
--- a/main/http_api.c
+++ b/main/http_api.c
@@ -24,16 +24,6 @@ static const char *TAG = "http_api";
 #define MAX_BODY_BYTES   2048
 #define MIN_IDLE_TIMEOUT 5000
 
-static const char *state_name(viewport_run_state_t s)
-{
-    return (s == VIEWPORT_STATE_AWAKE) ? "awake" : "asleep";
-}
-
-static const char *orientation_name(viewport_orientation_t o)
-{
-    return (o == VIEWPORT_ORIENTATION_LANDSCAPE) ? "landscape" : "portrait";
-}
-
 // ============================================================================
 // GET /state
 // ============================================================================
@@ -54,7 +44,8 @@ static esp_err_t state_get_handler(httpd_req_t *req)
                              : cJSON_CreateNull());
     cJSON_AddStringToObject(root, "version", VIEWPORT_VERSION);
     cJSON_AddBoolToObject  (root, "configured", st->configured);
-    cJSON_AddStringToObject(root, "state", state_name(st->state));
+    cJSON_AddStringToObject(root, "state",
+        (st->state == VIEWPORT_STATE_AWAKE) ? "awake" : "asleep");
     cJSON_AddNumberToObject(root, "uptime_ms", (double)up_ms);
     cJSON_AddItemToObject  (root, "last_frame_ms_ago",
         last_age_ms < 0 ? cJSON_CreateNull()
@@ -97,7 +88,8 @@ static esp_err_t config_get_handler(httpd_req_t *req)
         st->scrypted_url[0]  ? cJSON_CreateString(st->scrypted_url)
                              : cJSON_CreateNull());
     cJSON_AddNumberToObject(root, "idle_timeout_ms", (double)st->idle_timeout_ms);
-    cJSON_AddStringToObject(root, "orientation", orientation_name(st->orientation));
+    cJSON_AddStringToObject(root, "orientation",
+        (st->orientation == VIEWPORT_ORIENTATION_LANDSCAPE) ? "landscape" : "portrait");
     cJSON_AddNumberToObject(root, "brightness", (double)st->brightness);
 
     viewport_state_unlock();
@@ -254,10 +246,7 @@ static esp_err_t config_post_handler(httpd_req_t *req)
     }
 
     if (brightness_changed && display_is_up()) {
-        viewport_state_lock();
-        uint8_t b = viewport_state_get()->brightness;
-        viewport_state_unlock();
-        display_set_brightness(b);
+        display_set_brightness(bright);
     }
     if (name_or_orient_changed) {
         mdns_service_refresh();
@@ -317,15 +306,6 @@ static esp_err_t respond_status(httpd_req_t *req, const char *status, const char
     return httpd_resp_send(req, body, body ? HTTPD_RESP_USE_STRLEN : 0);
 }
 
-static void expected_dims(uint16_t *w, uint16_t *h)
-{
-    viewport_state_lock();
-    bool portrait = (viewport_state_get()->orientation == VIEWPORT_ORIENTATION_PORTRAIT);
-    viewport_state_unlock();
-    if (portrait) { *w = 480; *h = 800; }
-    else          { *w = 800; *h = 480; }
-}
-
 static esp_err_t frame_post_handler(httpd_req_t *req)
 {
     // Content-Type must be image/jpeg.
@@ -383,7 +363,7 @@ static esp_err_t frame_post_handler(httpd_req_t *req)
     }
 
     uint16_t want_w, want_h;
-    expected_dims(&want_w, &want_h);
+    viewport_state_effective_dims(&want_w, &want_h);
     if (w != want_w || h != want_h) {
         viewport_state_lock();
         viewport_state_get()->decode_errors++;
@@ -439,11 +419,7 @@ esp_err_t http_api_start(void)
     cfg.server_port      = 80;
     cfg.max_uri_handlers = 8;
     cfg.lru_purge_enable = true;
-    // Default 4 KiB is tight: /config alone has ~2.4 KiB of stack locals
-    // (2 KiB body buffer + 256 B scrypted URL + 64 B name + cJSON frames)
-    // and POST /frame pushes a JPEG header onto the stack too. 8 KiB gives
-    // both handlers comfortable headroom without doubling RAM usage.
-    cfg.stack_size       = 8192;
+    cfg.stack_size       = 8192;  // POST /config alone has ~2.4 KiB of stack locals
 
     httpd_handle_t server = NULL;
     ESP_RETURN_ON_ERROR(httpd_start(&server, &cfg), TAG, "httpd_start");
diff --git a/main/local_screens.c b/main/local_screens.c
index 7459d9a..f25754d 100644
--- a/main/local_screens.c
+++ b/main/local_screens.c
@@ -84,16 +84,6 @@ static void clear(uint16_t color)
     for (int i = 0; i < MAX_BUF_PX; ++i) s_fb[i] = color;
 }
 
-// Get current effective dimensions (rotated dims for portrait).
-static void effective_dims(uint16_t *w, uint16_t *h)
-{
-    viewport_state_lock();
-    viewport_orientation_t o = viewport_state_get()->orientation;
-    viewport_state_unlock();
-    if (o == VIEWPORT_ORIENTATION_PORTRAIT) { *w = 480; *h = 800; }
-    else                                    { *w = 800; *h = 480; }
-}
-
 // Draw a single 8x8 glyph at (ox, oy) into the effective-dim buffer with
 // integer scale. Pixels outside the buffer are clipped.
 static void draw_char(uint16_t fb_w, uint16_t fb_h, int ox, int oy,
@@ -199,26 +189,6 @@ void local_screens_overlay_dismiss(void)
     if (display_is_up()) display_sleep();
 }
 
-// Format `n` as a compact value with K / M suffix for thousands / millions.
-// Output max 8 chars, e.g. "168k", "30M", "1234".
-static void fmt_bytes(char *out, size_t cap, uint32_t n)
-{
-    if (n >= 1000000) snprintf(out, cap, "%um", (unsigned)(n / 1000000));
-    else if (n >= 1000) snprintf(out, cap, "%uk", (unsigned)(n / 1000));
-    else snprintf(out, cap, "%u", (unsigned)n);
-}
-
-// Format an uptime in milliseconds as "h:mm:ss" or "m:ss".
-static void fmt_uptime(char *out, size_t cap, uint64_t ms)
-{
-    uint64_t s = ms / 1000;
-    unsigned hh = (unsigned)(s / 3600);
-    unsigned mm = (unsigned)((s % 3600) / 60);
-    unsigned ss = (unsigned)(s % 60);
-    if (hh > 0) snprintf(out, cap, "%u:%02u:%02u", hh, mm, ss);
-    else        snprintf(out, cap, "%u:%02u",         mm, ss);
-}
-
 esp_err_t local_screens_show_info(void)
 {
     if (!s_fb) return ESP_ERR_INVALID_STATE;
@@ -293,9 +263,25 @@ esp_err_t local_screens_show_info(void)
     else              snprintf(idle_str, sizeof(idle_str), "%us",
                                (unsigned)(idle_ms / 1000));
 
-    char up_str[16];   fmt_uptime(up_str, sizeof(up_str), uptime_ms);
-    char heap_str[12]; fmt_bytes(heap_str,  sizeof(heap_str),  free_heap);
-    char psram_str[12]; fmt_bytes(psram_str, sizeof(psram_str), free_psram);
+    // Compact "h:mm:ss" / "m:ss" uptime
+    char up_str[20];
+    uint64_t up_s = uptime_ms / 1000;
+    unsigned hh = (unsigned)(up_s / 3600),
+             mm = (unsigned)((up_s % 3600) / 60),
+             ss = (unsigned)(up_s % 60);
+    if (hh) snprintf(up_str, sizeof(up_str), "%u:%02u:%02u", hh, mm, ss);
+    else    snprintf(up_str, sizeof(up_str), "%u:%02u",         mm, ss);
+
+    // Compact byte counts with k / M suffix
+    char heap_str[12], psram_str[12];
+    #define FMT_BYTES(buf, n) do { \
+        if      ((n) >= 1000000) snprintf((buf), sizeof(buf), "%uM", (unsigned)((n)/1000000)); \
+        else if ((n) >= 1000)    snprintf((buf), sizeof(buf), "%uk", (unsigned)((n)/1000));    \
+        else                     snprintf((buf), sizeof(buf), "%u",  (unsigned)(n));           \
+    } while (0)
+    FMT_BYTES(heap_str,  free_heap);
+    FMT_BYTES(psram_str, free_psram);
+    #undef FMT_BYTES
 
     const char *state_str = (state == VIEWPORT_STATE_AWAKE) ? "awake" : "asleep";
 
@@ -327,7 +313,7 @@ esp_err_t local_screens_show_info(void)
     // Auto-scale: largest scale where the longest line fits within 90% of
     // width and all lines + spacing fit within 90% of height.
     uint16_t w, h;
-    effective_dims(&w, &h);
+    viewport_state_effective_dims(&w, &h);
 
     size_t longest = 0;
     for (int i = 0; i < n_lines; ++i) {
@@ -363,7 +349,7 @@ esp_err_t local_screens_show_loading(void)
     if (!s_fb) return ESP_ERR_INVALID_STATE;
 
     uint16_t w, h;
-    effective_dims(&w, &h);
+    viewport_state_effective_dims(&w, &h);
     int scale = (w < 800) ? 4 : 5;
     int line_h = 8 * scale;
     int y = (h - line_h) / 2;
diff --git a/main/mdns_service.c b/main/mdns_service.c
index d389161..21cd464 100644
--- a/main/mdns_service.c
+++ b/main/mdns_service.c
@@ -14,48 +14,30 @@ static const char *SERVICE   = "_scrypted-viewport";
 static const char *PROTO     = "_tcp";
 static const uint16_t PORT   = 80;
 
-// Pull the current hostname + TXT values from viewport_state under the lock.
-static void snapshot_state(char *hostname, size_t host_cap,
-                           const char **resolution,
-                           const char **orientation,
-                           char *name, size_t name_cap)
-{
-    viewport_state_lock();
-    viewport_state_t *st = viewport_state_get();
-
-    if (st->viewport_name[0]) {
-        snprintf(hostname, host_cap, "viewport-%s", st->viewport_name);
-    } else {
-        snprintf(hostname, host_cap, "viewport");
-    }
-    *resolution  = viewport_state_resolution_str();
-    *orientation = (st->orientation == VIEWPORT_ORIENTATION_PORTRAIT)
-                       ? "portrait" : "landscape";
-    snprintf(name, name_cap, "%s", st->viewport_name[0] ? st->viewport_name : "");
-
-    viewport_state_unlock();
-}
-
-static esp_err_t apply_hostname(void)
+// Pull hostname + TXT values from viewport_state under one lock acquisition,
+// then push them at the mDNS service. mdns_service_add() rejects with
+// INVALID_ARG if the hostname isn't set, so order matters on first apply.
+static esp_err_t apply_state(bool include_hostname)
 {
     char hostname[80];
-    const char *resolution, *orientation;
     char name[64];
-    snapshot_state(hostname, sizeof(hostname),
-                   &resolution, &orientation,
-                   name, sizeof(name));
-    return mdns_hostname_set(hostname);
-}
-
-static esp_err_t apply_txt(void)
-{
-    char hostname[80];
     const char *resolution, *orientation;
-    char name[64];
-    snapshot_state(hostname, sizeof(hostname),
-                   &resolution, &orientation,
-                   name, sizeof(name));
 
+    viewport_state_lock();
+    viewport_state_t *st = viewport_state_get();
+    snprintf(hostname, sizeof(hostname), "viewport%s%s",
+             st->viewport_name[0] ? "-" : "",
+             st->viewport_name[0] ? st->viewport_name : "");
+    snprintf(name, sizeof(name), "%s",
+             st->viewport_name[0] ? st->viewport_name : "");
+    resolution  = viewport_state_resolution_str();
+    orientation = (st->orientation == VIEWPORT_ORIENTATION_PORTRAIT)
+                      ? "portrait" : "landscape";
+    viewport_state_unlock();
+
+    if (include_hostname) {
+        ESP_RETURN_ON_ERROR(mdns_hostname_set(hostname), TAG, "hostname_set");
+    }
     mdns_txt_item_t txt[] = {
         { "version",     VIEWPORT_VERSION },
         { "resolution",  resolution },
@@ -68,21 +50,21 @@ static esp_err_t apply_txt(void)
 
 esp_err_t mdns_service_start(void)
 {
-    // Order matters: mdns_service_add() rejects with INVALID_ARG if the
-    // hostname isn't set yet. So: init -> hostname -> service_add -> TXT.
-    ESP_RETURN_ON_ERROR(mdns_init(),           TAG, "mdns_init");
-    ESP_RETURN_ON_ERROR(apply_hostname(),       TAG, "hostname_set");
+    char hostname[80];
+    viewport_state_lock();
+    viewport_state_t *st = viewport_state_get();
+    snprintf(hostname, sizeof(hostname), "viewport%s%s",
+             st->viewport_name[0] ? "-" : "",
+             st->viewport_name[0] ? st->viewport_name : "");
+    viewport_state_unlock();
+
+    ESP_RETURN_ON_ERROR(mdns_init(),                       TAG, "mdns_init");
+    ESP_RETURN_ON_ERROR(mdns_hostname_set(hostname),        TAG, "hostname_set");
     ESP_RETURN_ON_ERROR(
         mdns_service_add(NULL, SERVICE, PROTO, PORT, NULL, 0),
         TAG, "service_add");
-    ESP_RETURN_ON_ERROR(apply_txt(),            TAG, "txt_set");
+    ESP_RETURN_ON_ERROR(apply_state(false),                 TAG, "txt_set");
 
-    char hostname[80];
-    const char *resolution, *orientation;
-    char name[64];
-    snapshot_state(hostname, sizeof(hostname),
-                   &resolution, &orientation,
-                   name, sizeof(name));
     ESP_LOGI(TAG, "mDNS up — %s.local advertising %s.%s.local on :%u",
              hostname, SERVICE, PROTO, PORT);
     return ESP_OK;
@@ -90,6 +72,5 @@ esp_err_t mdns_service_start(void)
 
 esp_err_t mdns_service_refresh(void)
 {
-    ESP_RETURN_ON_ERROR(apply_hostname(), TAG, "hostname_set");
-    return apply_txt();
+    return apply_state(true);
 }
diff --git a/main/net_eth.c b/main/net_eth.c
index f4dad8f..28ef782 100644
--- a/main/net_eth.c
+++ b/main/net_eth.c
@@ -150,11 +150,6 @@ esp_err_t net_eth_wait_for_ip(uint32_t timeout_ms)
     return (bits & BIT_GOT_IP) ? ESP_OK : ESP_ERR_TIMEOUT;
 }
 
-bool net_eth_is_up(void)
-{
-    return (xEventGroupGetBits(s_event_group) & BIT_GOT_IP) != 0;
-}
-
 const char *net_eth_get_ip_str(void)
 {
     return s_ip_str;
diff --git a/main/net_eth.h b/main/net_eth.h
index 23f2450..212e7f7 100644
--- a/main/net_eth.h
+++ b/main/net_eth.h
@@ -1,10 +1,8 @@
 #pragma once
 
-#include <stdbool.h>
 #include <stdint.h>
 #include "esp_err.h"
 
 esp_err_t net_eth_init(void);
 esp_err_t net_eth_wait_for_ip(uint32_t timeout_ms);
-bool net_eth_is_up(void);
 const char *net_eth_get_ip_str(void);
diff --git a/main/nvs_config.c b/main/nvs_config.c
index f6a9805..7f7586c 100644
--- a/main/nvs_config.c
+++ b/main/nvs_config.c
@@ -104,16 +104,3 @@ done:
     return err;
 }
 
-esp_err_t nvs_config_reset(void)
-{
-    nvs_handle_t h;
-    esp_err_t err = nvs_open(NS, NVS_READWRITE, &h);
-    if (err == ESP_ERR_NVS_NOT_FOUND) return ESP_OK;
-    if (err != ESP_OK) return err;
-
-    nvs_erase_all(h);
-    err = nvs_commit(h);
-    nvs_close(h);
-    ESP_LOGI(TAG, "NVS config cleared");
-    return err;
-}
diff --git a/main/nvs_config.h b/main/nvs_config.h
index 7688d81..b90577d 100644
--- a/main/nvs_config.h
+++ b/main/nvs_config.h
@@ -11,6 +11,3 @@ esp_err_t nvs_config_load(void);
 // Persist the current viewport_state to NVS atomically. The caller is expected
 // to have already mutated viewport_state under viewport_state_lock().
 esp_err_t nvs_config_save(void);
-
-// Clear all persisted config. Caller is responsible for rebooting.
-esp_err_t nvs_config_reset(void);
diff --git a/main/state_machine.c b/main/state_machine.c
index a4d4dab..0a6d491 100644
--- a/main/state_machine.c
+++ b/main/state_machine.c
@@ -12,21 +12,15 @@ static const char *TAG = "state";
 
 static esp_timer_handle_t s_idle_timer;
 
-static void arm_idle_timer_unlocked(void)
+// ms = idle_timeout_ms snapshotted under the caller's state lock.
+// ms == 0 disables the timer (caller's idle_timeout_ms feature).
+static void arm_idle_timer(uint32_t ms)
 {
-    viewport_state_lock();
-    uint32_t ms = viewport_state_get()->idle_timeout_ms;
-    viewport_state_unlock();
-    if (ms == 0) return;
     esp_timer_stop(s_idle_timer);
+    if (ms == 0) return;
     esp_timer_start_once(s_idle_timer, (uint64_t)ms * 1000ULL);
 }
 
-static void disarm_idle_timer(void)
-{
-    esp_timer_stop(s_idle_timer);
-}
-
 static void idle_timer_fired(void *arg)
 {
     ESP_LOGI(TAG, "idle timer expired — sleeping");
@@ -56,6 +50,7 @@ esp_err_t state_machine_set(viewport_run_state_t target)
     }
     st->state = target;
     bool configured = st->configured;
+    uint32_t idle_ms = st->idle_timeout_ms;
     viewport_state_unlock();
 
     if (target == VIEWPORT_STATE_AWAKE) {
@@ -67,10 +62,10 @@ esp_err_t state_machine_set(viewport_run_state_t target)
             if (configured) local_screens_show_loading();
             else            local_screens_show_info();
         }
-        arm_idle_timer_unlocked();
+        arm_idle_timer(idle_ms);
         ESP_LOGI(TAG, "AWAKE (%s)", configured ? "configured" : "no scrypted URL");
     } else {
-        disarm_idle_timer();
+        arm_idle_timer(0);
         if (display_is_up()) display_sleep();
         ESP_LOGI(TAG, "ASLEEP");
     }
@@ -80,9 +75,11 @@ esp_err_t state_machine_set(viewport_run_state_t target)
 void state_machine_frame_painted(void)
 {
     viewport_state_lock();
-    bool awake = (viewport_state_get()->state == VIEWPORT_STATE_AWAKE);
+    viewport_state_t *st = viewport_state_get();
+    bool awake = (st->state == VIEWPORT_STATE_AWAKE);
+    uint32_t idle_ms = st->idle_timeout_ms;
     viewport_state_unlock();
-    if (awake) arm_idle_timer_unlocked();
+    if (awake) arm_idle_timer(idle_ms);
 }
 
 void state_machine_set_local(viewport_run_state_t target)
diff --git a/main/viewport_state.c b/main/viewport_state.c
index 3ae8f81..7ddf737 100644
--- a/main/viewport_state.c
+++ b/main/viewport_state.c
@@ -13,8 +13,6 @@ void viewport_state_init(void)
 {
     memset(&s_state, 0, sizeof(s_state));
     s_state.configured      = false;
-    // State is always AWAKE or ASLEEP. UNCONFIGURED is reported via the
-    // `configured` flag, not as a state value. Boot is always asleep.
     s_state.state           = VIEWPORT_STATE_ASLEEP;
     s_state.brightness      = 80;
     s_state.idle_timeout_ms = 60000;
@@ -46,3 +44,12 @@ const char *viewport_state_resolution_str(void)
                ? "480x800"
                : "800x480";
 }
+
+void viewport_state_effective_dims(uint16_t *w, uint16_t *h)
+{
+    viewport_state_lock();
+    viewport_orientation_t o = s_state.orientation;
+    viewport_state_unlock();
+    if (o == VIEWPORT_ORIENTATION_PORTRAIT) { *w = 480; *h = 800; }
+    else                                    { *w = 800; *h = 480; }
+}
diff --git a/main/viewport_state.h b/main/viewport_state.h
index 3f6147f..4e6fbd6 100644
--- a/main/viewport_state.h
+++ b/main/viewport_state.h
@@ -46,3 +46,8 @@ void viewport_state_unlock(void);
 // on the current orientation. Caller-owned static storage; safe to read
 // without the lock (atomic snapshot).
 const char *viewport_state_resolution_str(void);
+
+// Effective width/height for the current orientation: portrait = 480x800
+// (rotated software-side from the panel's 800x480), landscape = 800x480.
+// Acquires the state lock internally.
+void viewport_state_effective_dims(uint16_t *w, uint16_t *h);