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, 9 insertions, 3 deletions

diff --git a/test/output.zig b/test/output.zig
index 21e9f04c..07a1ce23 100644
--- a/test/output.zig
+++ b/test/output.zig
@@ -575,6 +575,12 @@ test "EffectCode lists readable virtual sources used by this backend" {
     const p = try Pardes.init(std.testing.allocator, .{ .tty_only = true });
     defer p.deinit();
 
+    if (!pardes.memory.limits.embedded_sources) {
+        const before = p.active;
+        try std.testing.expect(p.executeBuiltinLine(0, "EffectCode PanelSlide"));
+        try std.testing.expectEqual(before, p.active);
+        return error.SkipZigTest;
+    }
     try std.testing.expect(p.executeBuiltinLine(0, "EffectCode PanelSlide"));
     const out = p.panes[p.active].?.file.?;
     try std.testing.expectEqualStrings(config.effect_code_buffer, std.fs.path.basename(out.path));
@@ -1035,10 +1041,10 @@ test "identical result refresh keeps warm content caches without allocation" {
     const style_ptr = file.highlights.ptr;
     const highlight_start = file.highlight_start;
     const selected = result.vsel;
-    const event_node = pardes.filesystem.Node.of(result.serial, .event);
-    const opened = pardes.filesystem.handle(p, .{ .tag = 0, .op = .open, .node = event_node });
+    const event_node = pardes.ctlfs.Node.of(result.serial, .event);
+    const opened = pardes.ctlfs.handle(p, .{ .tag = 0, .op = .open, .node = event_node });
     try std.testing.expectEqual(.ok, opened.status);
-    defer _ = pardes.filesystem.handle(p, .{ .tag = 0, .op = .release, .node = event_node, .handle = opened.handle });
+    defer _ = pardes.ctlfs.handle(p, .{ .tag = 0, .op = .release, .node = event_node, .handle = opened.handle });
 
     for (0..32) |_| {
         const incoming = try p.gpa.dupe(u8, text);