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

tools/CONTRACT.md

@@ -180,7 +180,7 @@ Scaffold a new wiki page of any type.
 
 - 0    success
 - 1    A page with this title already exists, the type is unknown, or a `--set` value is invalid
-- 1    The title is not a valid file name (forbidden character, control character, reserved name such as `CON` or `Index`, trailing dot or space, empty), collides with another page by case or Unicode normalization, or the target file already exists
+- 1    The title is not a valid file name (forbidden character, control character, reserved name such as `CON` or `Index`, trailing dot or space, empty), collides with another page by case or Unicode normalization, the target file already exists, or the target path is over the 160-character path budget
 - 1    A `raw_files` path does not exist
 - 1    A capture field the type-spec requires is missing, or set to `unknown`
 - 1    `--resume` with a type other than `project`
@@ -192,7 +192,7 @@ Scaffold a new wiki page of any type.
 **ON FAILURE**
 
 - A page with this title already exists, the type is unknown, or a `--set` value is invalid -> Not transient - fix the argument and retry once
-- The title is not a valid file name (forbidden character, control character, reserved name such as `CON` or `Index`, trailing dot or space, empty), collides with another page by case or Unicode normalization, or the target file already exists -> Not transient - choose another title and retry once. Nothing was created, and for `new project` no tracker project either
+- The title is not a valid file name (forbidden character, control character, reserved name such as `CON` or `Index`, trailing dot or space, empty), collides with another page by case or Unicode normalization, the target file already exists, or the target path is over the 160-character path budget -> Not transient - choose another (for the budget: a shorter) title and retry once. Nothing was created, and for `new project` no tracker project either
 - A `raw_files` path does not exist -> Not transient - fix the path and retry once
 - A capture field the type-spec requires is missing, or set to `unknown` -> Pass it explicitly (e.g. `--set fidelity=verbatim --set authority=reporting`), then retry once
 - `--resume` with a type other than `project` -> Drop `--resume` and retry once
@@ -208,6 +208,7 @@ Scaffold a new wiki page of any type.
 **NOTES**
 
 - A title becomes a file name, so it must be valid and unique on Windows and macOS as well as Linux, whichever platform runs the command and whichever root the type writes to. The rule is `kb/CONTRACT.md` § Titles are identifiers; it is checked on the full title, after `title_prefix`.
+- The target's path below the instance root may be at most 160 characters, counted in UTF-16 code units the way Windows counts MAX_PATH, so a Windows checkout without long paths keeps working. A longer one is refused, for every root, naming the length and how much shorter it has to get.
 - `new` never overwrites: a file already at the target - or one a case-insensitive file system would treat as the same file - is refused for every root, `instructions/` included.
 - The type-spec drives everything: fields, directory (`base_dir`/`layout`), title prefix, and template. `types list`/`types describe` show what a type requires.
 - A schema `default:` is materialized only for a field the schema also lists in `required:`.
@@ -475,14 +476,14 @@ Rename a page, or repoint references that name a page that never existed.
 - 0    success
 - 1    `--from` equals `--to`
 - 1    Neither `--from` nor `--to` is a page
-- 1    The `--to` title is already taken - also by a page that differs only in case or Unicode normalization, or by a file in the page's directory - or is not a valid file name (see `kb/CONTRACT.md` § Titles are identifiers)
+- 1    The `--to` title is already taken - also by a page that differs only in case or Unicode normalization, or by a file in the page's directory - or is not a valid file name, or would put the page's path over the path budget (see `kb/CONTRACT.md` § Titles are identifiers)
 - 1    A page write failed partway; nothing was renamed on disk
 
 **ON FAILURE**
 
 - `--from` equals `--to` -> Fix the arguments and retry once
 - Neither `--from` nor `--to` is a page -> Create the page first with `wikitool new`, or drop the reference with `wikitool xref remove`
-- The `--to` title is already taken - also by a page that differs only in case or Unicode normalization, or by a file in the page's directory - or is not a valid file name (see `kb/CONTRACT.md` § Titles are identifiers) -> Choose another title and retry once. Checked under `--dry-run` too
+- The `--to` title is already taken - also by a page that differs only in case or Unicode normalization, or by a file in the page's directory - or is not a valid file name, or would put the page's path over the path budget (see `kb/CONTRACT.md` § Titles are identifiers) -> Choose another, or a shorter, title and retry once. Checked under `--dry-run` too
 - A page write failed partway; nothing was renamed on disk -> Check `git status`, resolve the write failure (permissions/disk), then re-run the full command - safe, since each page's rewrite is idempotent
 
 **NEVER**
@@ -495,7 +496,7 @@ Rename a page, or repoint references that name a page that never existed.
 - If `--from` is *not* a page but is referenced, it instead repoints those references onto the existing `--to` page and moves nothing - the fix for a reference spelled `act_runner` when the page is `Act Runner`.
 - Each page's rewrite is idempotent, so a re-run as-is is safe. If a write fails midway, nothing is renamed on disk and the error lists what was updated.
 - `--dry-run` lists every page it would change; run it first to see the blast radius.
-- Only `--to` is checked against the title rule. A page whose current title breaks it (`lint`'s Unportable Titles) can always be renamed away from it, and a title that differs from the page's own only by case (`Foo` to `FOO`) is allowed.
+- Only `--to` is checked against the title rule and the path budget (160 UTF-16 code units for the whole path below the instance root). A page whose current title breaks either (`lint`'s Unportable Titles and Long Paths) can always be renamed away from it, and a title that differs from the page's own only by case (`Foo` to `FOO`) is allowed.
 
 **SEE ALSO**
 
@@ -583,14 +584,14 @@ Move a page (or every misplaced page) to the directory its type-spec computes.
 - 0    success
 - 1    Neither or both of `--page`/`--reconcile` given
 - 1    The named page is not found, or has no `type:` to compute a placement from
-- 1    The destination already holds an entry with the same name, or one that differs only in case or Unicode normalization (a pre-existing duplicate-stem collision) - refused rather than silently skipped
+- 1    The destination already holds an entry with the same name, or one that differs only in case or Unicode normalization (a pre-existing duplicate-stem collision), or its path would be over the path budget - refused rather than silently skipped
 - 1    `--reconcile` failed partway
 
 **ON FAILURE**
 
 - Neither or both of `--page`/`--reconcile` given -> Fix the arguments and retry once
 - The named page is not found, or has no `type:` to compute a placement from -> Fix the title, or give the page its `type:`, then retry once
-- The destination already holds an entry with the same name, or one that differs only in case or Unicode normalization (a pre-existing duplicate-stem collision) - refused rather than silently skipped -> Resolve the collision, then retry
+- The destination already holds an entry with the same name, or one that differs only in case or Unicode normalization (a pre-existing duplicate-stem collision), or its path would be over the path budget - refused rather than silently skipped -> Resolve the collision, or `wikitool rename` the page to a shorter title, then retry
 - `--reconcile` failed partway -> Safe to retry as-is - `--reconcile` only re-moves what is still misplaced
 
 **NEVER**
@@ -600,6 +601,7 @@ Move a page (or every misplaced page) to the directory its type-spec computes.
 **NOTES**
 
 - Moves a page to the directory its type-spec computes for its current frontmatter (`base_dir` + `layout`, the same rule `new` places a page by) - never to a hand-chosen destination; there is no `--to <dir>`.
+- A destination whose path would be over the path budget (160 UTF-16 code units below the instance root) is refused, and `--reconcile` skips such a page and names it, as it does for an occupied destination - `wikitool rename` the page to a shorter title.
 - `--reconcile` applies it corpus-wide: every misplaced page moves in one call, and a second run reports nothing left to do. It fixes `lint`'s `Misplaced Pages` (advisory) and `Nested Pages` (hard) findings.
 - Neither mode touches a body or a frontmatter field, and the page's title - its only identity in the wiki - never changes; only the file moves.
 - A directory a move empties is removed with it, so a page nested below its area leaves no leftover directory behind.
@@ -1116,6 +1118,7 @@ Run structural lint checks against kb/.
 - Advisory only: `see-also` edges whose reverse direction already carries a specific label - never migration-gated.
 - Advisory only: a collection past the catalog's per-area shard threshold that has no areas to shard, reported with the split its subtype field would produce, and only when that split puts every resulting area at or under the threshold.
 - Advisory only: source pages sitting in the `unclassified` catalog slot.
+- Advisory only: Long Paths - a file under `kb/` or `raw/` whose path below the instance root is over 160 UTF-16 code units, the budget that keeps a Windows checkout without long paths working. Reported as `{path, length}`; a corpus over the budget breaks no lint run. `wikitool rename` is the fix for a page.
 - Advisory only: quote-limit overages (>2 blockquotes/page).
 - Prints only the sections that found something and always writes the full report to `reports/Lint Report <date>.md` (or `--markdown`), naming the path. `--full` prints everything; `--json` prints the findings and writes nothing.
 - Exits 0 whatever it finds unless `--fail-on-error` is passed.
@@ -1124,7 +1127,7 @@ Run structural lint checks against kb/.
 
 - `wiki-lint` skill - the procedure that runs this
 - `wikitool move --reconcile` - fixes Misplaced and Nested Pages
-- `wikitool rename` - fixes Unportable Titles
+- `wikitool rename` - fixes Unportable Titles and, for a page, Long Paths
 - `wikitool log status` - whether a full lint is due
 
 #### `search`
@@ -1400,7 +1403,7 @@ Promote one or more files from `incoming/` into `raw/`.
 **EXIT STATUS**
 
 - 0    success
-- 1    raw accept: A file does not exist, is not under `incoming/`, or is nested more than one level below it; two files in one call share a filename; or a target path already exists
+- 1    raw accept: A file does not exist, is not under `incoming/`, or is nested more than one level below it; two files in one call share a filename; a target path already exists; or a target path would be over the path budget (160 UTF-16 code units below the instance root)
 - 1    raw accept: `--fidelity`/`--authority` is missing, or names `unknown` or a value outside the schema's enum
 - 1    raw accept: The target name is already occupied anywhere under `raw/` by something the call does not own
 - 1    raw accept: `--page` names an unknown page or one with no `raw_files:` yet, an existing `raw_files:` entry is missing on disk, a file to be moved has more than one owning page, or `--page` would overwrite an already-set `fidelity`/`authority` with a different value
@@ -1410,7 +1413,7 @@ Promote one or more files from `incoming/` into `raw/`.
 
 **ON FAILURE**
 
-- raw accept: A file does not exist, is not under `incoming/`, or is nested more than one level below it; two files in one call share a filename; or a target path already exists -> Fix the named argument and retry once
+- raw accept: A file does not exist, is not under `incoming/`, or is nested more than one level below it; two files in one call share a filename; a target path already exists; or a target path would be over the path budget (160 UTF-16 code units below the instance root) -> Fix the named argument and retry once. For a path over the budget, rename the file in `incoming/` to something shorter - the refusal comes before anything moves, so `incoming/` and `raw/` are unchanged
 - raw accept: `--fidelity`/`--authority` is missing, or names `unknown` or a value outside the schema's enum -> Pass both with a valid value, then retry once
 - raw accept: The target name is already occupied anywhere under `raw/` by something the call does not own -> Not fixed by retrying: the refusal names `--replaces` (same source, new edition) and renaming in `incoming/` (a separate source) as the two routes, and neither is the tool's to pick. Show the message to the user and wait
 - raw accept: `--page` names an unknown page or one with no `raw_files:` yet, an existing `raw_files:` entry is missing on disk, a file to be moved has more than one owning page, or `--page` would overwrite an already-set `fidelity`/`authority` with a different value -> Fix the named argument and retry once; a different capture value on an existing page is a new edition - `--replaces`