feat: path budget - a file's path stays at 160 characters or fewer; new, rename, move and raw accept refuse more, lint reports Long Paths (#163)

Files changed:
- CHANGES.md
- README.md
- VERSION
- instructions/page-lifecycle.md
- kb/CONTRACT.md
- tools/CONTRACT.md
- tools/chemenu/commands/_util.py
- tools/chemenu/commands/lint.py
- tools/chemenu/commands/new_page.py
- tools/chemenu/commands/page_ops.py
- tools/chemenu/commands/raw_cmd.py
- tools/chemenu/lint_core.py
- tools/chemenu/tests/test_lint.py
- tools/chemenu/tests/test_new_page.py
- tools/chemenu/tests/test_page_ops.py
- tools/chemenu/tests/test_raw_cmd.py
- tools/chemenu/tests/test_titles.py
- tools/chemenu/titles.py

README.md

@@ -326,6 +326,9 @@ Ingest incoming/my-notes.md
   no reserved names such as `CON` or `Index`, no trailing dot, and no second page whose title
   differs only by case. `wikitool new` and `wikitool rename` refuse such titles, `wikitool lint`
   reports existing ones, and `kb/CONTRACT.md` § Titles are identifiers has the full rule
+- A file's whole path below the instance root stays at 160 characters or fewer, so a Windows
+  checkout works without long paths: `new`, `rename`, `move` and `raw accept` refuse a longer
+  one, and `lint` reports existing ones as Long Paths (advisory; `wikitool rename` is the fix)
 - **Titles follow the subject's own established name, not the wiki's language.** `Act Runner` and
   `GitOps Ownership Model` keep theirs. A title is the only identifier a page has - it also lives
   in every wikilink and citation id pointing at it - so translating one is a rename, never an