feat(app): media keys and desktop media widget, keep the screen on during a film

- MPRIS on Linux and SMTC on Windows through souvlaki: play/pause, next,
  previous, stop and seeking from media keys and the panel widget, with
  the title, episode, duration and the cached cover as a file:// URL
- the screensaver is held off while a film plays on the player page,
  through the desktop portal with org.freedesktop.ScreenSaver as the
  fallback, and SetThreadExecutionState on Windows. mpv's own
  stop-screensaver has no window to act for under the render API

Cargo.lock

@@ -609,6 +609,12 @@ dependencies = [
  "digest 0.10.7",
 ]
 
+[[package]]
+name = "block"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0d8c1fef690941d3e7788d328517591fecc684c084084702d6ff1641e993699a"
+
 [[package]]
 name = "block-buffer"
 version = "0.10.4"
@@ -1029,6 +1035,36 @@ version = "0.5.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0c9ea0ac24bc397ab3c98583a3c9ba74fa56b09a4449bbe172b9b1ddb016027a"
 
+[[package]]
+name = "cocoa"
+version = "0.24.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f425db7937052c684daec3bd6375c8abe2d146dca4b8b143d6db777c39138f3a"
+dependencies = [
+ "bitflags 1.3.2",
+ "block",
+ "cocoa-foundation",
+ "core-foundation 0.9.4",
+ "core-graphics 0.22.3",
+ "foreign-types 0.3.2",
+ "libc",
+ "objc",
+]
+
+[[package]]
+name = "cocoa-foundation"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8c6234cbb2e4c785b456c0644748b1ac416dd045799740356f8363dfe00c93f7"
+dependencies = [
+ "bitflags 1.3.2",
+ "block",
+ "core-foundation 0.9.4",
+ "core-graphics-types",
+ "libc",
+ "objc",
+]
+
 [[package]]
 name = "codespan-reporting"
 version = "0.13.1"
@@ -1136,6 +1172,19 @@ version = "0.8.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "773648b94d0e5d620f64f280777445740e61fe701025087ec8b57f45c791888b"
 
+[[package]]
+name = "core-graphics"
+version = "0.22.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2581bbab3b8ffc6fcbd550bf46c355135d16e9ff2a6ea032ad6b9bf1d7efe4fb"
+dependencies = [
+ "bitflags 1.3.2",
+ "core-foundation 0.9.4",
+ "core-graphics-types",
+ "foreign-types 0.3.2",
+ "libc",
+]
+
 [[package]]
 name = "core-graphics"
 version = "0.23.2"
@@ -1145,7 +1194,7 @@ dependencies = [
  "bitflags 1.3.2",
  "core-foundation 0.9.4",
  "core-graphics-types",
- "foreign-types",
+ "foreign-types 0.5.0",
  "libc",
 ]
 
@@ -1377,6 +1426,15 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "dbus-crossroads"
+version = "0.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "64bff0bd181fba667660276c6b7ebdc50cff37ce593e7adf9e734f89c8f444e8"
+dependencies = [
+ "dbus",
+]
+
 [[package]]
 name = "dbus-secret-service"
 version = "4.1.0"
@@ -2024,6 +2082,15 @@ dependencies = [
  "bytemuck",
 ]
 
+[[package]]
+name = "foreign-types"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f6f339eb8adc052cd2ca78910fda869aefa38d22d5cb648e6485e4d3fc06f3b1"
+dependencies = [
+ "foreign-types-shared 0.1.1",
+]
+
 [[package]]
 name = "foreign-types"
 version = "0.5.0"
@@ -2031,7 +2098,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d737d9aa519fb7b749cbc3b962edcf310a8dd1f4b67c91c4f83975dbdd17d965"
 dependencies = [
  "foreign-types-macros",
- "foreign-types-shared",
+ "foreign-types-shared 0.3.1",
 ]
 
 [[package]]
@@ -2045,6 +2112,12 @@ dependencies = [
  "syn 3.0.3",
 ]
 
+[[package]]
+name = "foreign-types-shared"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "00b0228411908ca8685dba7fc2cdd70ec9990a6e753e89b6ac91a84c40fbaf4b"
+
 [[package]]
 name = "foreign-types-shared"
 version = "0.3.1"
@@ -3183,6 +3256,15 @@ version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "112b39cec0b298b6c1999fee3e31427f74f676e4cb9879ed1a121b43661a4154"
 
+[[package]]
+name = "malloc_buf"
+version = "0.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "62bb907fe88d54d8d9ce32a3cceab4218ed2f6b7d35617cafe9adf84e43919cb"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "matchers"
 version = "0.2.0"
@@ -3503,6 +3585,15 @@ dependencies = [
  "syn 2.0.119",
 ]
 
+[[package]]
+name = "objc"
+version = "0.2.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "915b1b472bc21c53464d6c8461c9d3af805ba1ef837e1cac254428f4a77177b1"
+dependencies = [
+ "malloc_buf",
+]
+
 [[package]]
 name = "objc-sys"
 version = "0.3.5"
@@ -4304,6 +4395,7 @@ name = "pstr-app"
 version = "0.4.2"
 dependencies = [
  "anyhow",
+ "dbus",
  "eframe",
  "egui",
  "futures",
@@ -4313,12 +4405,15 @@ dependencies = [
  "pstr-meta",
  "pstr-player",
  "pstr-stream",
+ "raw-window-handle",
  "serde",
  "serde_json",
  "sha2 0.10.9",
+ "souvlaki",
  "tokio",
  "tracing",
  "tracing-subscriber",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -5422,6 +5517,24 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "souvlaki"
+version = "0.8.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5855c8f31521af07d896b852eaa9eca974ddd3211fc2ae292e58dda8eb129bc8"
+dependencies = [
+ "base64 0.22.1",
+ "block",
+ "cocoa",
+ "core-graphics 0.22.3",
+ "dbus",
+ "dbus-crossroads",
+ "dispatch",
+ "objc",
+ "thiserror 1.0.69",
+ "windows",
+]
+
 [[package]]
 name = "spin"
 version = "0.9.9"
@@ -6561,6 +6674,15 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "windows"
+version = "0.44.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9e745dab35a0c4c77aa3ce42d595e13d2003d6902d6b08c9ef5fc326d08da12b"
+dependencies = [
+ "windows-targets 0.42.2",
+]
+
 [[package]]
 name = "windows-core"
 version = "0.62.2"
@@ -6933,7 +7055,7 @@ dependencies = [
  "cfg_aliases",
  "concurrent-queue",
  "core-foundation 0.9.4",
- "core-graphics",
+ "core-graphics 0.23.2",
  "cursor-icon",
  "dpi",
  "js-sys",