feat(fs): add a model-facing directory listing tool

`ctx.fs.listDir` has shipped since the filesystem seam gained it, with skill
discovery as its only consumer; the model-facing tool was deferred to a
separate decision. Nothing else could answer "what is in this directory":
`rg --files` backs glob and grep and never emits a directory entry, so an
empty directory is invisible, no output says which names are directories,
and no output gives an entry count.

`list` takes an optional `path`, defaulting to the session workspace so the
common question needs no argument, and returns the direct children of one
directory with their type. Two presentation rules carry it: directories sort
first, then files, then non-regular children, each alphabetically — so
truncation loses leaves rather than the tree — and the footer always states
the complete listing's size and composition, so a capped view can never read
as a whole directory.

It emits no `fs/observed`: seeing a filename is not reading a file, and a
listing must never satisfy the read-before-write gate.
This commit is contained in:
NI0317
2026-07-28 11:59:52 +08:00
parent 5888503d5f
commit d4614f92d6
48 changed files with 761 additions and 46 deletions

File diff suppressed because one or more lines are too long

File diff suppressed because one or more lines are too long

File diff suppressed because one or more lines are too long

File diff suppressed because one or more lines are too long