chore: bump version to 1.2.0

Updated:
- src-tauri/Cargo.toml
- src-tauri/tauri.conf.json
- package.json + package-lock.json
- snapcraft.yaml (root + packaging/)
- flake.nix
- Cargo.lock
- metainfo.xml (new release entry)
- README: Snap MPRIS limitation note with forum link

cc

src-tauri/Cargo.lock

@@ -516,9 +516,9 @@ checksum = "72b3254f16251a8381aa12e40e3c4d2f0199f8c6508fbecb9d91f575e0fbb8c6"
 
 [[package]]
 name = "bindgen"
-version = "0.71.1"
+version = "0.72.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5f58bf3d7db68cfbac37cfc485a8d711e87e064c3d0fe0435b92f7a407f9d6b3"
+checksum = "993776b509cfb49c750f11b8f07a46fa23e0a1386ffc01fb1e7d343efc387895"
 dependencies = [
  "bitflags 2.11.0",
  "cexpr",
@@ -3348,23 +3348,22 @@ dependencies = [
 
 [[package]]
 name = "mupdf"
-version = "0.5.0"
+version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3a6499267155b9ae03ff8e53c456d0bfff988b2647d62ff1df038f39ebe93a0c"
+checksum = "7a60c91abaf541e5291ca470efcb7d80d0ad834dcca7fa8f8576aa789a9813b1"
 dependencies = [
  "bitflags 2.11.0",
  "font-kit",
  "mupdf-sys",
- "num_enum",
  "once_cell",
  "zerocopy",
 ]
 
 [[package]]
 name = "mupdf-sys"
-version = "0.5.0"
+version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "13e9a0d4e844ab50315d43312f3d62f72c77205b07c8ee21cbd4b52bdc2a9910"
+checksum = "182cb40642a37e5980a03285664c2c100f5dbde781165c137fd49ff9c06fd5c5"
 dependencies = [
  "bindgen",
  "cc",
@@ -4617,7 +4616,7 @@ dependencies = [
 
 [[package]]
 name = "qbz-nix"
-version = "1.1.20"
+version = "1.2.0"
 dependencies = [
  "aes-gcm",
  "alsa 0.9.1",