feat(clipboard): pass original JPEG/GIF through verbatim beside the PNG floor

Transcoding every image to PNG was the Phase-1 floor, but it bloats lossy
originals (a copied JPEG re-encoded lossless is 5-10x the bytes for zero
quality gain — feeding the render-timeout on constrained links) and flattens
GIFs to one frame. The wire already carries kind LISTS, so offer the original
format beside the portable fallback and let the destination pick:

- New wire kinds image/jpeg + image/gif (§3.5 extension; strings only, no
  protocol change). image/png stays the universal floor every peer accepts.
- macOS: public.jpeg / com.compuserve.gif rows pass through verbatim both
  directions; the PNG floor is announced whenever any image is present.
- Windows: registered JFIF/GIF formats read + promised verbatim; every image
  offer still promises CF_DIB, whose delayed render now fetches the richest
  offered kind (png > jpeg > gif) through the generalized image_to_dib.
- Linux maps gain the matching rows (native MIME pass-through).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Cargo.lock

@@ -560,6 +560,12 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "byteorder-lite"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f1fe948ff07f4bd06c30984e69f5b4899c516a3ef74f34df92a2df2ab535495"
+
 [[package]]
 name = "bytes"
 version = "1.12.0"
@@ -756,6 +762,12 @@ dependencies = [
  "cc",
 ]
 
+[[package]]
+name = "color_quant"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3d7b894f5411737b7867f4827955924d7c254fc9f4d91a6aad6b097804b1018b"
+
 [[package]]
 name = "colorchoice"
 version = "1.0.5"
@@ -1141,6 +1153,15 @@ dependencies = [
  "getrandom 0.3.4",
 ]
 
+[[package]]
+name = "fdeflate"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e6853b52649d4ac5c0bd02320cddc5ba956bdb407c4b75a2c6b75bf51500f8c"
+dependencies = [
+ "simd-adler32",
+]
+
 [[package]]
 name = "fec-rs"
 version = "0.1.0"
@@ -1495,6 +1516,16 @@ dependencies = [
  "polyval",
 ]
 
+[[package]]
+name = "gif"
+version = "0.14.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ee8cfcc411d9adbbaba82fb72661cc1bcca13e8bba98b364e62b2dba8f960159"
+dependencies = [
+ "color_quant",
+ "weezl",
+]
+
 [[package]]
 name = "gio"
 version = "0.22.6"
@@ -1988,6 +2019,23 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "image"
+version = "0.25.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85ab80394333c02fe689eaf900ab500fbd0c2213da414687ebf995a65d5a6104"
+dependencies = [
+ "bytemuck",
+ "byteorder-lite",
+ "color_quant",
+ "gif",
+ "moxcms",
+ "num-traits",
+ "png",
+ "zune-core",
+ "zune-jpeg",
+]
+
 [[package]]
 name = "indexmap"
 version = "2.14.0"
@@ -2386,6 +2434,16 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "moxcms"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bb85c154ba489f01b25c0d36ae69a87e4a1c73a72631fc6c0eb6dde34a73e44b"
+dependencies = [
+ "num-traits",
+ "pxfm",
+]
+
 [[package]]
 name = "nasm-rs"
 version = "0.3.2"
@@ -2805,6 +2863,7 @@ dependencies = [
  "anyhow",
  "ashpd",
  "futures-util",
+ "image",
  "libc",
  "punktfunk-core",
  "quinn",
@@ -3075,6 +3134,19 @@ version = "0.3.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "19f132c84eca552bf34cab8ec81f1c1dcc229b811638f9d283dceabe58c5569e"
 
+[[package]]
+name = "png"
+version = "0.18.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "60769b8b31b2a9f263dae2776c37b1b28ae246943cf719eb6946a1db05128a61"
+dependencies = [
+ "bitflags",
+ "crc32fast",
+ "fdeflate",
+ "flate2",
+ "miniz_oxide",
+]
+
 [[package]]
 name = "polling"
 version = "3.11.0"
@@ -3382,6 +3454,12 @@ dependencies = [
  "winresource",
 ]
 
+[[package]]
+name = "pxfm"
+version = "0.1.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d55d956fa96f5ec02be2e13af0e20391a5aa83d6a074e3ad368959d0fab299ea"
+
 [[package]]
 name = "pyrowave-sys"
 version = "0.13.0"
@@ -5202,6 +5280,12 @@ dependencies = [
  "rustls-pki-types",
 ]
 
+[[package]]
+name = "weezl"
+version = "0.1.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a28ac98ddc8b9274cb41bb4d9d4d5c425b6020c50c46f25559911905610b4a88"
+
 [[package]]
 name = "wide"
 version = "0.7.33"
@@ -6014,6 +6098,21 @@ version = "1.0.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b8848ee67ecc8aedbaf3e4122217aff892639231befc6a1b58d29fff4c2cabaa"
 
+[[package]]
+name = "zune-core"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cb8a0807f7c01457d0379ba880ba6322660448ddebc890ce29bb64da71fb40f9"
+
+[[package]]
+name = "zune-jpeg"
+version = "0.5.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "27bc9d5b815bc103f142aa054f561d9187d191692ec7c2d1e2b4737f8dbd7296"
+dependencies = [
+ "zune-core",
+]
+
 [[package]]
 name = "zvariant"
 version = "5.12.0"