Tests, licence, and the tooling to keep the repo consistent

A test suite with no dependencies beyond bash and the Python standard
library, run by one command:

  scripts/test.sh                    (or: make test)
  scripts/test.sh --windows [host]   adds the PowerShell suite over SSH

- tests/static.sh: script syntax, JSON validity, VERSION against the widget
  manifest and CHANGELOG, providers.json against the kinds, probes and checks
  the code implements (and ids that would shadow a command), qmllint and
  shellcheck when installed.
- tests/python: unit tests for cm-json.py - providers and the column contract
  bash depends on, the original three scaffolds byte for byte, every
  catalogue parser and the cache, session scan/dismiss/repair, rename,
  defaults, health, the cost guard.
- tests/cli: the CLI in a sandbox with its own HOME, CM_ROOT,
  CLAUDE_CONFIG_DIR and a file-only vault, against fake Ollama, LM Studio,
  keyed-gateway and proxy servers - preflight, presets, models, doctor, a real
  switch, sessions, and the key helper under a rename race.
- tests/windows: the same idea on a Windows host, with USERPROFILE pointed at
  a temp folder so the real install is never touched.

Also: MIT licence, CHANGELOG.md reconstructed from history, .editorconfig and
.gitattributes pinning LF everywhere (what the tree already is), and
scripts/bump-version.sh, since the version lives in two files and drifted
once before.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 smoido
+
+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.