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, 6 insertions, 1 deletions

diff --git a/src/panes.zig b/src/panes.zig
index 49e5d624..edd7038f 100644
--- a/src/panes.zig
+++ b/src/panes.zig
@@ -1014,6 +1014,8 @@ pub const File = struct {
         /// Equal means the screen matches disk.
         saved_revision: u32 = 0,
         watch_after_save: bool = false,
+        /// Seconds of the last content change, for the filesystem's stat; zero until edited.
+        mtime: u32 = 0,
         /// Non-null for a generated output buffer rather than an on-disk file.
         output: ?Output.State = null,
         mini: ?Mini.State = null,
@@ -1702,7 +1704,7 @@ pub const File = struct {
             const pane = slot orelse continue;
             if (pane.file) |*state| if (state == f) break i;
         } else return;
-        pardes.filesystem.noteReplace(p, id, false, f.content, new);
+        pardes.ctlfs.events.noteReplace(p, id, false, f.content, new);
     }
 
     pub fn setContent(p: *Pardes, f: *State, new: []u8) void {
@@ -1722,6 +1724,7 @@ pub const File = struct {
         p.gpa.free(f.content);
         f.content = new;
         f.revision +%= 1;
+        f.mtime = pardes.ctlfs.events.now();
         if (f.line_starts.len > 0) p.gpa.free(f.line_starts);
         f.line_starts = &.{};
         if (f.highlights.len > 0) p.tree_sitter_gpa.free(f.highlights);
@@ -2876,6 +2879,8 @@ pub const Output = struct {
             else => return error.NotAnEffect,
         }
         if (!setting.enabled(builtins.capabilities)) return error.EffectUnavailable;
+        // Without -Dembed-sources the paths would name nothing this build can open.
+        if (!limits.embedded_sources) return error.EffectUnavailable;
         const paths = effect_sources.forSetting(setting) orelse
             return error.EffectUnavailable;