M12: PRC reader: map the prc-rs licence for license-check (#1297)

The Double code table's attribution pointed its licence file at the
table's own source. `cargo xtask license-check` requires every asset's
licence file to be a LICENSES.toml document, so the gate failed.

Add prc-rs's LICENSE at the same commit as `licenses/prc-rs-LICENSE.txt`,
fetched unchanged, with its origin and hash in LICENSES.toml, and point
the attribution entry at it. The MIT notice stays in the table's header.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SqmHYx8FiWM5PcsoiErgp9

ATTRIBUTION.toml

@@ -2443,7 +2443,7 @@ title = "PRC Double prefix-code table (as a Rust table)"
 author = "Kristof Ralovich (prc-rs); the code table itself is defined by the PRC format (ISO 14739-1, working draft clause 11.17.2)"
 source = "Rows taken from prc-rs src/double.rs at commit 287b671bb5b31b05efb5ec1b98f7c359b9e4dd7d (https://github.com/ralovich/prc-rs), mechanically reformatted into (code length, code, entry) tuples; checked to be a complete prefix code by the tests in crates/prc/src/acof.rs. Data only: the code that reads the table lives in acof.rs. The MIT notice is kept in the file header."
 licence = "MIT"
-licence_file = "crates/prc/src/acof/table.rs"
+licence_file = "licenses/prc-rs-LICENSE.txt"
 kind = "data"
 usage = "Decodes every PRC Double (coordinates, transforms, colours) in 3D annotations' PRC streams. Non-visual data."
 sha256 = "8e705c5cde6a3ef778e8aca69759e38845b228b3f7f12949e587b19855d2114c"

LICENSES.toml

@@ -88,6 +88,13 @@ destination = "licenses/egui-emoji-icon-font-mit-license.txt"
 sha256 = "b9d2c1d909aa149996fd4c91dcb92b2362a04431640c1d200959da94caf8cde1"
 origin = "https://raw.githubusercontent.com/emilk/egui/0.36.2/crates/epaint_default_fonts/fonts/emoji-icon-font-mit-license.txt"
 
+[[document]]
+source = "licenses/prc-rs-LICENSE.txt"
+licences = ["MIT"]
+destination = "licenses/prc-rs-LICENSE.txt"
+sha256 = "ddb846513d92153d8fa16b18ed3e7c86953a582f0d2f49f02b29f1bd569dac58"
+origin = "https://raw.githubusercontent.com/ralovich/prc-rs/287b671bb5b31b05efb5ec1b98f7c359b9e4dd7d/LICENSE"
+
 [[document]]
 source = "vendor/hayro-interpret/LICENSE-APACHE"
 licences = ["Apache-2.0"]

licenses/prc-rs-LICENSE.txt

@@ -0,0 +1,7 @@
+Copyright (c) 2025,2026 Kristof Ralovich
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.