The tree's README and fs.md answer round 8's doc questions

The README's log line names newcol, delcol, ask, restored and restoredcol;
it says what $m is under 9ns --unix; and a build that embeds no sources no
longer lists src/ (derived from the build, and tested). fs.md says what the
rest of a typed line does after Kill for each shell (fish runs on, bash
abandons it), that Exec <text> in a .py pane runs a command and never the
REPL, and why appending to a tag wants printf and a leading blank.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 12 insertions, 1 deletions

diff --git a/src/fs.zig b/src/fs.zig
index 65e5d276..8be728a6 100644
--- a/src/fs.zig
+++ b/src/fs.zig
@@ -19,7 +19,14 @@ const Reply = tree.Reply;
 const E = tree.E;
 
 /// The served README; tree.zig answers it.
-pub const help = @embedFile("fs-help.txt");
+/// The tree's README; a build that embeds no sources lists no src/.
+pub const help = help: {
+    const raw = @embedFile("fs-help.txt");
+    if (limits.embedded_sources) break :help raw;
+    const both = "os/, src/   the host filesystem; the editor's own sources";
+    const at = std.mem.indexOf(u8, raw, both) orelse @compileError("fs-help.txt no longer lists os/, src/");
+    break :help raw[0..at] ++ "os/         the host filesystem" ++ raw[at + both.len ..];
+};
 
 /// Host filesystem nodes: the root, and one hashed node per path a client walked to.
 pub const os_root: u64 = (1 << 63) + 2;
@@ -1364,3 +1371,7 @@ pub fn unmount(p: *Pardes, name: []const u8) !void {
 test {
     _ = tree;
 }
+
+test "the tree's README lists src/ only when the build serves it" {
+    try std.testing.expectEqual(limits.embedded_sources, std.mem.indexOf(u8, help, "src/") != null);
+}