Dired is the file surface, not a rider on one: before Stage 0 (#162)
pmacs had no way to open a file by path, and browsing is the half a
user reaches for when they do not already know the path. Stage 1 ships
the view.
builtin/runtime/dired.lua: one buffer per directory named by the
canonical path (Q#DR2) with an ownership check before any paint (F7);
read-only intercept plus round-trip input (Q#DR3); a `dired` major mode
carrying mode-scoped keys (Q#DR8) -- RET/f visit, ^ parent, n/p, g
revert, q quit, s sort; cursor re-seated by basename across every
wholesale repaint (Q#DR9); file visits through
`pmacs.window.display_file` and directory descent through dired's own
window (Q#DR10); `C-x d` / `C-x C-j`; and `dired.kill-when-opening`
through the config registry.
Two Rust changes, both narrow:
* `read_dir` grows per-entry tolerance behind an opt (Q#DR6). Five
per-entry conditions used to fail the entire listing, so a plain
refresh of a busy directory could just fail; the module doc's claim
that a tolerant wrapper was "the package's job" was false, because
the primitive hands Lua one structured error and no partial vec.
Per-entry readdir/lstat/readlink failures and non-UTF-8 symlink
targets now land in an `errors` channel; parent-level failures and
non-UTF-8 *names* stay fatal. The tolerance travels in the settled
payload, so the Lua boundary keeps the bare-array shape the frozen
M8.2 fixture consumes and never has to look the job back up. The read
ops' opts parsing now rejects unknown keys, so a typo'd `tolerant`
cannot silently degrade to the fatal contract.
* `normalize_buffer_path` is exposed as `pmacs.path.canonicalize`
rather than mirrored in Lua. Q#DR2 named exposure the preferred end
state; it needs no borrow plumbing, so dired's name-dedup and
`display_file`'s `find_buffer_for_path` dedup cannot fork, and the
mirror's Stage 2 removal is not owed.
tests/dired_acceptance.rs covers framing items 1-16 (22 tests), driven
through real key dispatch. Item 17 is the m8_1/m8_2/m8_3 gate.
One framing claim is corrected by the substrate: R2-3 expected a
dedicated dired panel to carry its dedication across a descent, but
`display_buffer` never replaces the buffer in a slot dedicated to
another one -- it discards every side-specific parameter and falls back
to the document window (Q#BP3 2.iii). Dired does not try to unpin the
user's panel; both arms are pinned.
