tools: command records, Git group - NOTES as bullets, one exit line per cause, examples and prohibitions (#142)

Files changed:
- CHANGES.md
- VERSION
- tools/CONTRACT.md
- tools/README.md
- tools/chemenu/cli_contract.py
- tools/chemenu/commands/cite_cmd.py
- tools/chemenu/commands/dist_cmd.py
- tools/chemenu/commands/docs_verify.py
- tools/chemenu/commands/doctor.py
- tools/chemenu/commands/eval_cmd.py
- tools/chemenu/commands/git_publish.py
- tools/chemenu/commands/index_build.py
- tools/chemenu/commands/instructions_cmd.py
- tools/chemenu/commands/links_cmd.py
- tools/chemenu/commands/lint.py
- tools/chemenu/commands/log_append.py
- tools/chemenu/commands/migrate_cmd.py
- tools/chemenu/commands/new_page.py
- tools/chemenu/commands/page_ops.py
- tools/chemenu/commands/provenance_cmd.py
- tools/chemenu/commands/raw_cmd.py
- tools/chemenu/commands/review_cmd.py
- tools/chemenu/commands/run_budget.py
- tools/chemenu/commands/search.py
- tools/chemenu/commands/task_cmd.py
- tools/chemenu/commands/touch.py
- tools/chemenu/commands/types_cmd.py
- tools/chemenu/commands/upload_cmd.py
- tools/chemenu/commands/upstream_cmd.py
- tools/chemenu/commands/version_cmd.py
- tools/chemenu/commands/work_cmd.py
- tools/chemenu/commands/xref.py
- tools/chemenu/tests/test_cli_contract.py
- tools/chemenu/tests/test_docs_verify.py

tools/chemenu/commands/provenance_cmd.py

@@ -103,10 +103,10 @@ def coverage(json_out: bool = typer.Option(False, "--json", help="Print raw find
     "page -> its sources -> their raw files",
     failures=(cli_contract.Failure(
         label="",
-        exit_1="Neither or both of `--raw`/`--page` given, `--raw` names a file no source page "
+        cause="Neither or both of `--raw`/`--page` given, `--raw` names a file no source page "
         "covers (reported as a plain finding plus exit 1, not the usual `ERROR`-prefixed "
         "rejection), or `--page` names an unknown page",
-        retry="Fix the argument and retry",
+        reaction="Fix the argument and retry",
     ),),
 ))
 def trace(
@@ -219,8 +219,8 @@ def build_provenance_index(kb_dir: Path, raw_dir: Path) -> str:
     "pages)",
     failures=(cli_contract.Failure(
         label="",
-        exit_1="Rare I/O error only",
-        retry="Safe to retry freely",
+        cause="Rare I/O error only",
+        reaction="Safe to retry freely",
     ),),
 ))
 def rebuild_index(