Inkwell is licensed AGPL-3.0-only (#6227)

#6227 "License Inkwell under AGPL-3.0-only: LICENSE file and SPDX
identifier". The operator chose AGPL-3.0-only, as for FabledStash (#6212).

- LICENSE is the canonical GNU AGPL v3 text from gnu.org: 661 lines, md5
  eb1e647870add0502f8f010b19de32af, the same file as FabledStash's.
- AGPL-3.0-only is declared in pyproject.toml, frontend/package.json (and
  its lockfile root entry), the four crates, and tauri.conf.json's bundle.
- The pacman package declared MIT; it now declares AGPL-3.0-only.
- pyproject's build floor moves to setuptools>=77, the first release that
  reads `license` as an SPDX expression.
- The README's Licence section names the licence, links LICENSE, and
  states the network clause in one sentence.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

desktop/src-tauri/Cargo.toml

@@ -8,6 +8,7 @@ name = "inkwell-desktop"
 version = "0.2.0"
 description = "Inkwell desktop — local-first Keep-style thought capture"
 authors = ["bvandeusen"]
+license = "AGPL-3.0-only"
 edition = "2021"
 # The executable is named below, not inferred from this package name. Off so the
 # inferred `inkwell-desktop` target and the explicit one can't both claim

desktop/src-tauri/tauri.conf.json

@@ -43,6 +43,7 @@
     "active": true,
     "targets": ["deb", "appimage"],
     "category": "Utility",
+    "license": "AGPL-3.0-only",
     "linux": {
       "deb": {
         "conflicts": ["thought-sync"],