Flatten the 9P control tree and move it out of fs.zig

The served tree loses the self/ level: /index /ctl /new /log /screen
/listeners /pane/<n>/... /os, with /src only in -Dembed-sources=true builds
(default off, on for esp32p4). ctl speaks the editor's own language with two
lowercase verbs, look TEXT and exec TEXT, plus acme's addr verbs; the new/
factory directory becomes one clone file; cons is gone (exec Msg); name and
sel are files; stats report real lengths, modes and mtimes; /log streams
pane new/del/rename/save events. The tree code lives in src/ninep/
(tree, pane, ctl, addr, pty, events, screen, sources); fs.zig keeps host
access, mounts, resolution and find/grep. Same engine and transports.
README (fs-help.txt) and docs rewritten; tests updated and extended.

Co-Authored-By: Claude Fable 5.1 <[email protected]>

1 files changed, 38 insertions, 1 deletions

diff --git a/test/ninep.py b/test/ninep.py
index b128cc8a..6c625951 100644
--- a/test/ninep.py
+++ b/test/ninep.py
@@ -116,7 +116,44 @@ class Client:
             self.close(fid)
 
     def screen(self):
-        return json.loads(self.read('/self/screen'))
+        return json.loads(self.read('/screen'))
+
+    def walk(self, path):
+        names = [part for part in os.fspath(path).split('/') if part]
+        self.fid += 1
+        fid = self.fid
+        oldfid = 1
+        try:
+            for start in range(0, max(1, len(names)), 16):
+                part = names[start:start + 16]
+                reply = self.rpc(110, struct.pack('<IIH', oldfid, fid, len(part)) +
+                                 b''.join(string(name) for name in part))
+                if struct.unpack_from('<H', reply)[0] != len(part):
+                    raise FileNotFoundError(path)
+                oldfid = fid
+            return fid
+        except BaseException:
+            try:
+                self.close(fid)
+            except OSError:
+                pass
+            raise
+
+    def stat(self, path):
+        """Tstat without an open: {'name', 'mode', 'length', 'mtime', 'qid'}."""
+        fid = self.walk(path)
+        try:
+            reply = self.rpc(124, struct.pack('<I', fid))
+        finally:
+            self.close(fid)
+        size = struct.unpack_from('<H', reply, 2)[0]
+        record = reply[4:4 + size]
+        qid = record[6:19]
+        mode, _, mtime, length = struct.unpack_from('<IIIQ', record, 19)
+        name_len = struct.unpack_from('<H', record, 39)[0]
+        name = record[41:41 + name_len].decode()
+        return {'name': name, 'mode': mode & 0o777, 'dir': bool(mode & 0x80000000),
+                'length': length, 'mtime': mtime, 'qid': qid}
 
     def write(self, path, data, truncate=False):
         fid = self.open(path, 1 | (16 if truncate else 0))