contributing: Use SPDX copyright tags in more complicated file headers

[wenzeslaus]

Converts the 31 files that #7743 left out because their notices needed reading rather than pattern matching.

• Names and years preserved as is; notices naming several people are split into one line per person, with a shared range repeated on each line.
• Organization names with punctuation stay on one line (mundialis GmbH & Co.KG, GDF Hannover bR, http://www.gdf-hannover.de).
• Text interleaved with the old notices survives unchanged, including the third-party permission notice in r.texture and the RMIT license text in v.delaunay.

The largest split, vector/v.vol.rst:

- * COPYRIGHT:    (C) 1989, 1993, 2000 L. Mitas,  H. Mitasova,
- *               I. Kosinovsky, D. Gerdes, J. Hofierka
-
- *               This program is free software under the GNU General Public
- *               License (>=v2). Read the file COPYING that comes with GRASS
- *               for details.
+ * SPDX-FileCopyrightText: 1989, 1993, 2000 L. Mitas
+ * SPDX-FileCopyrightText: 1989, 1993, 2000 H. Mitasova
+ * SPDX-FileCopyrightText: 1989, 1993, 2000 I. Kosinovsky
+ * SPDX-FileCopyrightText: 1989, 1993, 2000 D. Gerdes
+ * SPDX-FileCopyrightText: 1989, 1993, 2000 J. Hofierka
+ * SPDX-FileCopyrightText: Other GRASS authors
+ * SPDX-License-Identifier: GPL-2.0-or-later

Two decisions here go beyond the mechanical rules of #7743:

• The r.geomorphon clause (C) Scientific idea of geomorphon copyrighted to authors. is dropped. It was likely meant as an acknowledgement of the authors of the geomorphon concept rather than as a record of a legal right, and that acknowledgement is given by the tool documentation, which cites their papers and lists them as authors.
• Three imagery tools (i.albedo, i.aster.toar, i.evapo.time) whose prose named an unversioned GNU Lesser General Public License while pointing at the GPL COPYING file are converted to GPL-2.0-or-later, following the COPYING reference.

Like #7743, this should technically merge after #7749, which defines "Other GRASS authors", but it does not have to.

Written with AI assistance (Claude Code with Opus 4.8 and Fable 5); the decisions are the author's.

Details: per-file resolutions and how it was checked (AI generated)

Splits into one line per holder

• vector/v.vol.rst/* (8 files): five holders, shared years 1989, 1993, 2000 repeated on each line.
• raster/r.stats.zonal/main.c: 2007,2008 Martin Schroeder and 2007,2008 Glynn Clements.
• scripts/r.tileset/r.tileset.py: 2006-2009 Cedric Shoc and 2006-2009 Martin Landa, spelling as written.
• scripts/r.out.xyz/r.out.xyz.py: two clauses, each with its own year, 2006 Hamish Bowman and 2008 Glynn Clements.

Single holders whose names carry punctuation

2019 mundialis GmbH & Co.KG (two files), 2003 University of Sannio (BN), Benevento, Italy, and 2004, 2005 GDF Hannover bR, http://www.gdf-hannover.de, each on one line exactly as written.

Interleaved text kept in place

The NOTE in lib/gis/open_misc.c, the modification history in vector/v.perturb/main.c, the port note in scripts/r3.in.xyz/r3.in.xyz.py, the attribution paragraph in macos/build_grass_app.bash, the third-party permission notice below the header in raster/r.texture/main.c, and the RMIT license text in vector/v.delaunay/main.c are all byte-identical to before.

v.delaunay (8 files)

(C) RMIT 1993 becomes SPDX-FileCopyrightText: 1993 RMIT, years first like every other line in the tree. The team clause becomes the standard bare collective line, so its 2008-2009 years are not carried over; this is the one place in this PR where years from the old notice are not preserved.

Checked

Each of the 31 files was changed by a single reviewed replacement applied by a small script that asserts the old text occurs exactly once, the trailing bytes are unchanged, no COPYRIGHT: field remains, and exactly one license identifier results. No emitted C line exceeds 78 columns, and pre-commit run on all 31 files passes with nothing reformatted. lib/vector/rtree/docs/MAILS, an archived 2002 email that quotes a header inside a permission request, remains excluded and untouched.

[neteler]

I have scanned it, looks good to me