Record where a linear DNG too large for one texture goes

ARCH §5.3 still described only a tile cache nobody built; it now says
what 0.19.0 tiles and what it does not: a linear DNG past PROXY_EDGE
opens on a reduced copy, a finer render samples a full-resolution
window, and the export is cut into halo-grown tiles. display-and-
extension.md's FR-DSP-2 row said absent, outstanding.md said the halo
had nothing to read it and that such a file fell to the embedded
preview.

rawler now builds from third_party, which ARCH's stack table and §3.2,
the root Cargo.toml's comment ("two upstream crates ... for Android")
and third_party/README.md's bump procedure did not know; the README
also names each vendored crate's licence. panorama.md and the manual
say a composite this wide develops and exports.

Cargo.toml

@@ -276,11 +276,12 @@ opt-level = 0
 lto = "thin"
 codegen-units = 1
 
-# Two upstream crates carry a local patch so that the Android build can draw
-# with wgpu on a rotated display (technical-debt.md TD-1). Both are exact
-# copies of the version the lockfile already resolves, plus that patch;
-# third_party/README.md says what was changed and how to carry it forward
-# when Slint or wgpu moves.
+# Three upstream crates carry a local patch: wgpu-hal and Slint's Skia
+# renderer so that the Android build can draw with wgpu on a rotated display
+# (technical-debt.md TD-1), and rawler so that a linear DNG wider than 16 700
+# pixels decodes. Each is an exact copy of the version the lockfile already
+# resolves, plus its patch; third_party/README.md says what was changed and
+# how to carry it forward when Slint, wgpu or rawler moves.
 [patch.crates-io]
 wgpu-hal = { path = "third_party/wgpu-hal-29.0.4" }
 i-slint-renderer-skia = { path = "third_party/i-slint-renderer-skia-1.17.1" }